125876 + Interview Questions in General QA

1.	What is banking of roads? Give an example of it.
Answer» Vehicles while taking a turn cannot incline themselves to one side to get the required centripetal force. To provide necessary centripetal force without slipping. The outer edge of the road is raised over the inner edge.

Discussion

2.	A car is taking a sudden turn to the left. A person in the seat finds himself sliding towards the floor, Explain, indicating the forces acting on the passenger on the car at this instant.
Answer» The passenger in the front seat slides towards door i.e., away from the centre due to centrifugal force acting on the passenger.

Discussion

3.	Give an example for three dimen-sional motion.
Answer» Flight of Aeroplane or movement of gas molecule in space.

Discussion

4.	A body moves along a circle of radius 3m. What is the distance travelled. When it completes one circle?
Answer» Given: radius, r = 3m. Distance travelled by. the body when it completes one circle = circumference of the circle = 2 π r = 2 × 3.4 × 3 = 18.84 m.

4.

A body moves along a circle of radius 3m. What is the distance travelled. When it completes one circle?

Answer»

Given: radius, r = 3m.

Distance travelled by. the body when it completes one circle

= circumference of the circle

= 2 π r = 2 × 3.4 × 3

= 18.84 m.

Discussion

5.	What is the work done by centripetal force?
Answer» Zero is the work done by centripetal force.

Discussion

6.	Give an example when a body moving with uniform speed has acceleration.
Answer» A body moving in a circle has an acceleration of v²/r towards the centre of the circle.

Discussion

7.	Read each statement below carefully and state, with reasons, if it is true or false:(a) The net acceleration of a particle in circular motion is always along the radius of the circle towards the centre.(b) The velocity vector of a particle at a point is always along the tangent to the path of the particle at that point.(c) The acceleration vector of a particle in uniform circular motion averaged over one cycle is a null vector.
Answer» (a) False The net acceleration of a particle in circular motion is not always directed along the radius of the circle toward the centre. It happens only in the case of uniform circular motion. (b) True At a point on a circular path, a particle appears to move tangentially to the circular path. Hence, the velocity vector of the particle is always along the tangent at a point. (c) True In uniform circular motion (UCM), the direction of the acceleration vector points toward the centre of the circle. However, it constantly changes with time. The average of these vectors over one cycle is a null vector.

7.

Read each statement below carefully and state, with reasons, if it is true or false:(a) The net acceleration of a particle in circular motion is always along the radius of the circle towards the centre.(b) The velocity vector of a particle at a point is always along the tangent to the path of the particle at that point.(c) The acceleration vector of a particle in uniform circular motion averaged over one cycle is a null vector.

Answer»

(a) False
The net acceleration of a particle in circular motion is not always directed along the radius of the circle toward the centre. It happens only in the case of uniform circular motion.

(b) True
At a point on a circular path, a particle appears to move tangentially to the circular path. Hence, the velocity vector of the particle is always along the tangent at a point.

(c) True
In uniform circular motion (UCM), the direction of the acceleration vector points toward the centre of the circle. However, it constantly changes with time. The average of these vectors over one cycle is a null vector.

Discussion

8.	A body travels one round in a circle of radius ‘R’- What is thedisplacement and.distance traveled.
Answer» The displacement of a body = 0 The distance travelled = 2nR

Discussion

9.	What is angle of banking? Give the expression for it.
Answer» The angle through which the outer edge of the roads are raised is called the angle of banking. The angle of banking is given by, θ = tan^-1\((\frac {v^2} {rg})\) where m is the mass, v is the velocity and r is the radius.

9.

What is angle of banking? Give the expression for it.

Answer»

The angle through which the outer edge of the roads are raised is called the angle of banking. The angle of banking is given by,

θ = tan^-1\((\frac {v^2} {rg})\)

where m is the mass, v is the velocity and r is the radius.

Discussion

10.	What are the units of angular speed ?
Answer» Radian/second (rad s^-1).

Discussion

11.	Read each statement below carefully and state, with reasons, if it is true or false:a) The net acceleration of a particle in circular motion is always along the radius of the circle towards the centre. b) The velocity vector of a particle at a point is always along the tangent to the path of the particle at that point. c) The acceleration vector of a particle in uniform circular motion averaged over one cycle is a null vector.
Answer» a) False The net acceleration of a particle in circular motion is not always directed along the radius of the circle toward the centre. It happens only in the case of uniform circular motion. b) True At a point on a circular path, a particle appears to move tangentially to the circular path. Hence, the velocity vector of the particle is always along the tangent at a point. c) True In uniform circular motion (UCM), the direction of the acceleration vector points toward the centre of the circle. However, it constantly changes with time. The average of these vectors over one cycle is a null vector.

11.

Read each statement below carefully and state, with reasons, if it is true or false:a) The net acceleration of a particle in circular motion is always along the radius of the circle towards the centre. b) The velocity vector of a particle at a point is always along the tangent to the path of the particle at that point. c) The acceleration vector of a particle in uniform circular motion averaged over one cycle is a null vector.

Answer»

a) False

The net acceleration of a particle in circular motion is not always directed along the radius of the circle toward the centre. It happens only in the case of uniform circular motion.

b) True

At a point on a circular path, a particle appears to move tangentially to the circular path. Hence, the velocity vector of the particle is always along the tangent at a point.

c) True

In uniform circular motion (UCM), the direction of the acceleration vector points toward the centre of the circle. However, it constantly changes with time. The average of these vectors over one cycle is a null vector.

Discussion

12.	What is the direction of velocity vector of a particle in circular motion?
Answer» At every point along tangent to the circular path.

Discussion

13.	Read each statement below carefully and state with reasons, it is true of false:The average speed of a particle (defined as total path length divided by the time taken to cover the path is either greater or equal to the magnitude of average-velocity of the particle over the same time interval).
Answer» True, average speed depends upon total path-length which can be equal or more than the magnitude of displacement vector of the particle and average velocity depends upon the displacement vector. Thus, average speed can be equal or greater than the magnitude of average velocity.

Discussion

14.	Define period of revolution of a body.
Answer» It is the time taken by the body to complete one revolution.

Discussion

15.	Define angular velocity.
Answer» The rate of angular displacement is called angular velocity.

Discussion

16.	Is circular motion possible at constant speed or at constant velocity ? Explain.
Answer» Circular motion is possible at constant speed because in circular motion, the magnitude of the velocity,i.e., speed remains constant while the direction of motion changes continuously.

Discussion

17.	Read each statement below carefully and state with reasons, it is true of false:The total path length is always equal to the magnitude of the displacement vector of a particle.
Answer» False, total path-length can also be more than the magnitude of the displacement vector of a particle.

Discussion

18.	What is the angular velocity of the hour hand ?
Answer» The hour hand completes one rotation in 12 hours or 12 x 3600 sec. The angle through which it rotates in 12 hours = 2π radians. ∴ The angular velocity of hour hand = (2π/12 x 3600) = 0.0001455 rad s^-1.

18.

What is the angular velocity of the hour hand ?

Answer»

The hour hand completes one rotation in 12 hours or 12 x 3600 sec. The angle through which it rotates in 12 hours = 2π radians.

∴ The angular velocity of hour hand

= (2π/12 x 3600) = 0.0001455 rad s^-1.

Discussion

19.	The velocity of a particle is constant in magnitude but not in direction. What is the nature of trajectory?
Answer» The particle moves on a curved path. The instantaneous direction will be tangential to the path at every point.

Discussion

20.	Read each statement below carefully and state, with reasons and examples, if it is true or false:A scalar quantity is one that(a) is conserved in a process(b) can never take negative values(c) must be dimensionless(d) does not vary from one point to another in space(e) has the same value for observers with different orientations of axes
Answer» (a) False Despite being a scalar quantity, energy is not conserved in inelastic collisions. (b) False Despite being a scalar quantity, temperature can take negative values. (c) False Total path length is a scalar quantity. Yet it has the dimension of length. (d) False A scalar quantity such as gravitational potential can vary from one point to another in space. (e) True The value of a scalar does not vary for observers with different orientations of axes.

Discussion

21.	Define equal vectors.
Answer» Two vectors are said to be equal vectors if they have equal magnitudes and same directions.

Discussion

22.	Read each statement below carefully and state, with reasons and examples, if it is true of false:A scalar quantity is one that.(a) Is conserved in a process.(b) Can never take negative values.
Answer» (a) It is false. Energy (a scalar quantity) is not conserved in inelastic collisions. (b) It is false. The temperature a ( a scalar quantity) of a system cannot be negative.

22.

Read each statement below carefully and state, with reasons and examples, if it is true of false:A scalar quantity is one that.(a) Is conserved in a process.(b) Can never take negative values.

Answer»

(a) It is false. Energy (a scalar quantity) is not conserved in inelastic collisions.

(b) It is false. The temperature a ( a scalar quantity) of a system cannot be negative.

Discussion

23.	Define scalar.Given two examples.
Answer» The physical quantity which has only magnitude and no direction is called a scalar quantity. For Example: mass, work, length, speed distance etc.

23.

Define scalar.Given two examples.

Answer»

The physical quantity which has only magnitude and no direction is called a scalar quantity.

For Example: mass, work, length, speed distance etc.

Discussion

24.	Define vector quantities.Give two examples.
Answer» The physical quantities having both magnitude as well as direction are called vector. Examples are: Velocity, acceleration, force, displacement etc.

24.

Define vector quantities.Give two examples.

Answer»

The physical quantities having both magnitude as well as direction are called vector.

Examples are: Velocity, acceleration, force, displacement etc.

Discussion

25.	Observe the relationship between the first two words and fill in the blanks.1. Ascariasis: Ascaris,Elephantiasis:-2. Cannabinoids: Hashish,Opioids:-
Answer» 1. Wuchereria 2. Heroin

25.

Observe the relationship between the first two words and fill in the blanks.1. Ascariasis: Ascaris,Elephantiasis:-2. Cannabinoids: Hashish,Opioids:-

Answer»

1. Wuchereria

2. Heroin

Discussion

26.	A drug called morphine is obtained from(a) Rauwoifia serpentina (b) Cannabis sativa(c) Cajanus cajan(d) Papaver somniferum
Answer» (d) Papaver somniferum

Discussion

27.	The part of internal ear responsible for hearing is ………………. (a) cochlea (b) semicircular canal (c) utriculus (d) sacculus
Answer» Correct answer is (a) cochlea

Discussion

28.	Which is the vitamin present in Rhodopsin? (a) Vitamin A (b) Vitamin B (c) Vitamin C (d) Vitamin D
Answer» Correct answer is (a) Vitamin A

Discussion

29.	………………. is attached to the eardrum. (a) Malleus (b) Incus (c) Stapes (d) Cochlea
Answer» Correct answer is (a) Malleus

Discussion

30.	The space within cochlea is known as ………………. (a) scala vestibule (b) scala tympani (c) aqueous chamber (d) scala media
Answer» Correct answer is (d) scala media

Discussion

31.	Eustachian tube is present in ………………. (a) external ear (b) internal ear (c) heart (d) middle ear
Answer» Correct answer is (d) middle ear

Discussion

32.	The frequency of vibration of a string depends of on, (i) tension in the string (ii) mass per unit length of string, (iii) vibrating length of the string. Establish dimensionally the relation for frequency.
Answer» n ∝ I^a T^b m^c , [I] = M⁰L¹T⁰ [T] = M¹ L¹ T^–2 (force) [M] = M¹L^–1 T⁰ [M⁰L⁰T^–1] = [M⁰ L¹ T⁰]^a [M¹ L¹ T^–2]^b [M¹ L^–1 T⁰]^c b + c = 0 a + b – c = 0 - 2b = -1 => b = 1/2 c = - 1/2 a = 1 n ∝ 1/l √T/m.

32.

The frequency of vibration of a string depends of on, (i) tension in the string (ii) mass per unit length of string, (iii) vibrating length of the string. Establish dimensionally the relation for frequency.

Answer»

n ∝ I^a T^b m^c , [I] = M⁰L¹T⁰

[T] = M¹ L¹ T^–2 (force)

[M] = M¹L^–1 T⁰

[M⁰L⁰T^–1] = [M⁰ L¹ T⁰]^a [M¹ L¹ T^–2]^b [M¹ L^–1 T⁰]^c

b + c = 0

a + b – c = 0

- 2b = -1 => b = 1/2

c = - 1/2 a = 1

n ∝ 1/l √T/m.

Discussion

33.	Which part of the eye contains cells which are sensitive to light ?
Answer» Retina part of the eye contains cells which are sensitive to light .

Discussion

34.	The escape velocity v of a body depends on– (i) the acceleration due to gravity ‘g’ of the planet, (ii) the radius R of the planet. Establish dimensionally the relation for the escape velocity.
Answer» v α g^a R^b ⇒ v = k g^a R^b, K → dimensionless proportionality constant [v] = [g]^a [R]^b [M⁰L¹T^–1] = [M⁰L¹T^–2]^a [M⁰ L¹ T⁰]^b equating powers 1 = a + b – 1 = – 2a ⇒ a = 1/2 b = 1 – a = 1 - 1/2 = 1/2 ∴ v = k √gR

34.

The escape velocity v of a body depends on– (i) the acceleration due to gravity ‘g’ of the planet, (ii) the radius R of the planet. Establish dimensionally the relation for the escape velocity.

Answer»

v α g^a R^b ⇒ v = k g^a R^b,

K → dimensionless proportionality constant

[v] = [g]^a [R]^b

[M⁰L¹T^–1] = [M⁰L¹T^–2]^a [M⁰ L¹ T⁰]^b

equating powers 1 = a + b

– 1 = – 2a ⇒ a = 1/2

b = 1 – a = 1 - 1/2 = 1/2

∴ v = k √gR

Discussion

35.	Write an account of position and structure of pituitary gland.
Answer» Pituitary gland (Hypophysis): I. Position : Pituitary or Hypophysis is located on the ventral side of brain below the hypothalamus. Infundibulum or hypophyseal stalk attaches pituitary to hypothalamus just behind the optic chiasma. It is well protected in sella turcica which is a depression of the sphenoid bone of the skull. II. Morphological structure of pituitary- gland: The pituitary gland shows two distinct regions : Anterior lobe or adenohypophysis and posteriorlobe or neurohypophysis. (1) Adenohypophysis or Anterior lobe : It is the largest lobe of the gland and forms about 75% of pituitary gland. It develops as an outgrowth called Rathke’s pouch from the roof of embryonic buccal cavity. It has three divisions, viz. pars tuberalis, pars distalis and pars intermedia. (i) Pars tuberalis : Tubular region present below the hypothalamus is known as pars tuberalis. It is like a collar around the infundibulum. It is non-secretory in nature. (ii) Pars distalis : The largest anterior region which is secretory in nature is called pars distalis. It is made up of loose cords of epitheloid secretory cells which are separated by reticular connective tissue containing blood sinusoids. It is connected to the hypothalamus by portal system formed by blood sinusoids. (iii) Pars intermedia : The narrow cleft between the pars distalis and pars nervosa of neuro – hypophysis is called the intermediate part or pars intermedia. It is reduced, less developed and non-functional in human being. (2) Neuro-hypophysis or Posterior lobe : The posterior lobe of the pituitary which is attached to hypothalamus by infundibular stalk is called neuro-hypophysis. It is smaller and constitute 25% of pituitary. It has the following three parts: 1. Median eminence : The swollen median part of the hypothalamus where infundibulum gets attached is called median eminence. 2. Infundibulum : Infundibulum is the hypophyseal stalk that helps in attachment of pituitary gland to the hypothalamus. It contains mainly the axonic fibres of neurosecretory cells present in hypothalamus. It forms the major connection of hypothalamo-hypophysis axis. 3. Pars nervosa : The lowermost, larger region of neuro-hypophysis that contains axons is called pars nervosa. It acts as a neurohaerhal organ and contains specialized cells called pituicytes.

35.

Write an account of position and structure of pituitary gland.

Answer»

Pituitary gland (Hypophysis):

I. Position : Pituitary or Hypophysis is located on the ventral side of brain below the hypothalamus. Infundibulum or hypophyseal stalk attaches pituitary to hypothalamus just behind the optic chiasma. It is well protected in sella turcica which is a depression of the sphenoid bone of the skull.

II. Morphological structure of pituitary- gland: The pituitary gland shows two distinct regions : Anterior lobe or adenohypophysis and posteriorlobe or neurohypophysis.

(1) Adenohypophysis or Anterior lobe : It is the largest lobe of the gland and forms about 75% of pituitary gland. It develops as an outgrowth called Rathke’s pouch from the roof of embryonic buccal cavity. It has three divisions, viz. pars tuberalis, pars distalis and pars intermedia.

(i) Pars tuberalis : Tubular region present below the hypothalamus is known as pars tuberalis. It is like a collar around the infundibulum. It is non-secretory in nature.

(ii) Pars distalis : The largest anterior region which is secretory in nature is called pars distalis. It is made up of loose cords of epitheloid secretory cells which are separated by reticular connective tissue containing blood sinusoids. It is connected to the hypothalamus by portal system formed by blood sinusoids.

(iii) Pars intermedia : The narrow cleft between the pars distalis and pars nervosa of neuro – hypophysis is called the intermediate part or pars intermedia. It is reduced, less developed and non-functional in human being.

(2) Neuro-hypophysis or Posterior lobe : The posterior lobe of the pituitary which is attached to hypothalamus by infundibular stalk is called neuro-hypophysis. It is smaller and constitute 25% of pituitary. It has the following three parts:

1. Median eminence : The swollen median part of the hypothalamus where infundibulum gets attached is called median eminence.

2. Infundibulum : Infundibulum is the hypophyseal stalk that helps in attachment of pituitary gland to the hypothalamus. It contains mainly the axonic fibres of neurosecretory cells present in hypothalamus. It forms the major connection of hypothalamo-hypophysis axis.

3. Pars nervosa : The lowermost, larger region of neuro-hypophysis that contains axons is called pars nervosa. It acts as a neurohaerhal organ and contains specialized cells called pituicytes.

Discussion

36.	Class 7 Science MCQ Questions of Water: A Precious Resource with Answers?
Answer» Class 7 Science MCQ Questions of Water: A Precious Resource with Answers gave here covers Questions on the significance of water, natural mindfulness, the idea of the water cycle, a wellspring of groundwater, issues of water shortage across various areas we mean all syllabus. MCQ Questions for Class 7 Science given here center more around information building and help the students to have a more profound comprehension of the ideas. You can check the nitty-gritty detailed solutions of MCQ Questions for class 7 Science. Access the MCQ Questions with Answers of Class 7 Science and get a decent grasp on the ideas subsequently endeavor the test with certainty. Class 7 Science MCQ Questions of Light with Answer helps students to have more grounded nuts and bolts and covers all the concepts of Science. This might help you to understand and check your insight about the parts. Practice MCQ Questions for Class 7 Science 1. On which day the world water day is celebrated? (a) 23rd March (b) 22nd March (c) 21st March (d) None of these 2. Which year was observed as International Year of Fresh Water? (a) 2003 (b) 2004 (c) 2006 (d) 2002 3. Which of the following does not show water shortage? (a) Taps running dry (b) Long queue for getting water (c) Marches and protests for demand of water (d) A family gets three buckets of water per person per day 4. Seas and oceans are full of water on earth. However, a very small percentage of water present on earth is available for us. This percentage is roughly (a) 0.006% (b) 0.06% (c) 0.6% (d) 6% 5. Which of the following is a way to use water economically? (a) construction of bawris (b) Rainwater harvesting (c) Drip irrigation (d) Infiltration 6. The amount of water recommended by the United Nations for drinking, washing, cooking and maintaining proper hygiene per person per day is a minimum of (a) 5 litres (b) 15 litres (c) 30 litres (d) 50 litres 7. “Every Drop Counts” is a slogan related to (a) counting of drops of any liquid (b) counting of water drops (c) importance of water (d) importance of counting 8. Water cycle does not involve which of the following? (a) Evaporation (b) Condensation (c) Formation of clouds (d) Rainwater harvesting 9. Which of the following inhibits the seepage of rainwater into ground? (a) A pukka floor (b) playground (c) Grass lawn (d) Forest land 10. The cause of depletion of water table is: (a) increasing industries (b) water table (c) rain water (d) none of these 11. Steam is which form of water? (a) solid (b) liquid (c) gas (d) none of these 12. Snow and ice, are present as ________ at the poles of the earth, snow-covered mountains, and glaciers. (a) liquid form (b) the solid form (c) the gaseous form (d) none of the above 13. The solid parts of the earth’s crust called: (a) atmosphere (b) lithosphere (c) hydrosphere (d) none of these 14. Which of the following is a way to use water economically? (a) construction of bawris (b) Rainwater harvesting (c) Drip irrigation (d) Infiltration 15. The process of ground water getting stored between the layers of hard rock below the water table is known as (a) Infiltration (b) Aquifer (c) Water table (d) Bawri 16. River Yamuna is polluted near Delhi due to (a) Thermal plant on its bank (b) Water animals (c) Addition of untreated sewage (d) Rivers joining it 17. The traditional way of collecting water was: (a) bawaris (b) well (c) rivers (d) none of these 18. Plants loose water in form of (a) Liquid (b) Gases (c) Snow (d) Water vapour 19. Main source of water on earth is: (a) rain (b) snow (c) glaciers (d) all the above 20. The water below the ground is known as (a) groundwater (b) pure water (c) polluted water (d) none of these 21. Earth appear blue from sky due to presence of (a) Desert (b) Mountains (c) Land (d) Water 22. The process of seeping of water into the ground is called (a) Infiltration (b) Aquifer (c) Water table (d) Bawri 23. Water is chlorinated to (a) Kill germs (b) Change colour (c) Soften it (d) Improve its taste 24. Addition of harmful substance in water leads to (a) Algal bloom (b) Microbial growth (c) High oxygen demand (d) Water pollution 25. The process of changing water vapour into water is called (a) Boiling (b) Condensation (c) Evaporation (d) Sedimentation Answer: 1. Answer: (b) 22nd March Explanation: World Water Day is an annual United Nations (UN) observance day held on 22 March that highlights the importance of fresh water. The day is used to advocate for the sustainable management of freshwater resources. 2. Answer: (a) 2003 Explanation: Year 2003 was observed as the International Year of Freshwater to make people aware of this dwindling natural resource. 3. Answer: (d) A family gets three buckets of water per person per day Explanation: Water shortage is the lack of sufficient available water resources to meet the demands of water usage within a region.There seems no water shortage as three buckets of water per person is enough for satisfying their daily needs. 4. Answer: (a) 0.006% Explanation:The total amount of fresh water available for use is about 0.006% of the total water present on earth as about 97.4% of the total water on earth is in seas and ocean and 2% water is present in the form of glaciers and in polar ice caps. 5. Answer: (c) Drip irrigation Explanation: One such traditional practice listed above is construction of bawris which is actually constructing deep wells followed by steps made by mud deep in the ground. These bawris would get filled with water whenever there is rain and hence was used by villagers to carry out their daily chores and to collect water. 6. Answer: (d) 50 litres Explanation: The amount of water recommended by the United Nations for drinking, washing, cooking and maintaining proper hygiene is a minimum of 50 litres per person per day. This amount is about two and a half buckets of water per person per day. 7. Answer: (c) importance of water Explanation: Every drop counts' is the slogan related to the importance of water. Water is very important for humans as well as for animals. But fresh water is less than one percent of water available on the Earth. 8. Answer: (d) Rainwater harvesting Explanation: Liquid water evaporates into water vapor, condenses to form clouds, and precipitates back to earth in the form of rain and snow. The water cycle does not involve rainwater harvesting as it is the collection and storage of rain, rather than allowing it to run off. 9. Answer: (a) A pukka floor Explanation: A pukka floor is a cement floor which is impenetrable to water. Hence water cannot seep through the pukka floor. 10. Answer: (a) increasing industries Explanation: Every industry requires water in its production process. As a number of industries increases, more water is drawn from the ground. All of this result in depletion of the water table. 11. Answer: (c) gas Explanation: Steam is water in the gas phase. Steam that is saturated or superheated is invisible; however, "steam" often refers to wet steam, the visible mist or aerosol of water droplets formed as water vapour condenses. 12. Answer: (b) the solid form Explanation: Water can be found in liquid form in oceans, rivers, lakes and rain; in solid form in ice and snow; and as a gas (water vapour) in the atmosphere. 13. Answer: (b) lithosphere Explanation:The outermost layer, called the crust, is solid, too. Together, these solid parts are called the lithosphere. Earth's crust is made up of hard rocks. 14. Answer: (c) Drip irrigation Explanation: Drip irrigation is the method to use water economically. As in drip irrigation system the water is supplied drop by drop to plants which does not cause the wastage of water and supply as per the needs of the plants. 15. Answer: (b) Aquifer Explanation: An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand or salt). Ground water can be extracted using a water well. 16. Answer: (c) Addition of untreated sewage Explanation: Essentially, the release of poorly treated or even completely untreated sewage is responsible for the frothing and foaming of the river water. Surfactants and phosphates that originate from detergents used in households and industrial laundries, when released in the river untreated, create the foam. 17. Answer: (a) bawaris Explanation: Bawri were deep step wells built into the ground. It was the traditional way of rainwater harvesting. 18. Answer: (d) Water vapour Explanation: Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. Transpiration is essentially evaporation of water from plant leaves. 19. Answer: (a) rain Explanation: The main source of water is the rainwater. The water cycle is a process that involves evaporation, condensation and precipitation and the output is rainwater. The water source is important in the water cycle. 20. Answer: (a) groundwater Explanation: Groundwater, water that occurs below the surface of Earth, where it occupies all or part of the void spaces in soils or geologic strata. It is also called subsurface water to distinguish it from surface water, which is found in large bodies like the oceans or lakes or which flows overland in streams. 21. Answer: (d) Water Explanation: The Earth has been blue for over 4 billion years because of the liquid water on its surface. There is only one known planet with permanent bodies of liquid water at its surface: ours. Earth sciences allow us to explain why the Earth has almost always been blue: it's neither too warm nor too cold. 22. Answer: (a) Infiltration Explanation: Process of seeping of water into the ground is called infiltration . Infiltration is the process by which bulk of rainwater and melted snow soaks into subsurface soils and moves into rocks through cracks and pores, 23. Answer: (a) Kill germs Explanation: Water chlorination is the process of adding chlorine or chlorine compounds such as sodium hypochlorite to water. This method is used to kill bacteria, viruses and other microbes in water. In particular, chlorination is used to prevent the spread of waterborne diseases such as cholera, dysentery, and typhoid. 24. Answer: (d) Water pollution Explanation: The addition of any substance to water, which leads to change in its physical and chemical characteristic, is defined as water pollution. 25. Answer: (b) Condensation Explanation: The process of changing water vapour into water is called condensation.This is due to the change of gaseous state of water into liquid state. Some common examples of condensation are Formation of drops of water on the outside of a glass of ice water. ,Formation of dew on grass overnight. Click here for Practice MCQ Questions for Water: A Precious Resource Class 7

36.

Class 7 Science MCQ Questions of Water: A Precious Resource with Answers?

Answer»

Class 7 Science MCQ Questions of Water: A Precious Resource with Answers gave here covers Questions on the significance of water, natural mindfulness, the idea of the water cycle, a wellspring of groundwater, issues of water shortage across various areas we mean all syllabus. MCQ Questions for Class 7 Science given here center more around information building and help the students to have a more profound comprehension of the ideas. You can check the nitty-gritty detailed solutions of MCQ Questions for class 7 Science.

Access the MCQ Questions with Answers of Class 7 Science and get a decent grasp on the ideas subsequently endeavor the test with certainty. Class 7 Science MCQ Questions of Light with Answer helps students to have more grounded nuts and bolts and covers all the concepts of Science. This might help you to understand and check your insight about the parts.

Practice MCQ Questions for Class 7 Science

1. On which day the world water day is celebrated?

(a) 23rd March
(b) 22nd March
(c) 21st March
(d) None of these

2. Which year was observed as International Year of Fresh Water?

(a) 2003
(b) 2004
(c) 2006
(d) 2002

3. Which of the following does not show water shortage?

(a) Taps running dry
(b) Long queue for getting water
(c) Marches and protests for demand of water
(d) A family gets three buckets of water per person per day

4. Seas and oceans are full of water on earth. However, a very small percentage of water present on earth is available for us. This percentage is roughly

(a) 0.006%
(b) 0.06%
(c) 0.6%
(d) 6%

5. Which of the following is a way to use water economically?

(a) construction of bawris
(b) Rainwater harvesting
(c) Drip irrigation
(d) Infiltration

6. The amount of water recommended by the United Nations for drinking, washing, cooking and maintaining proper hygiene per person per day is a minimum of

(a) 5 litres
(b) 15 litres
(c) 30 litres
(d) 50 litres

7. “Every Drop Counts” is a slogan related to

(a) counting of drops of any liquid
(b) counting of water drops
(c) importance of water
(d) importance of counting

8. Water cycle does not involve which of the following?

(a) Evaporation
(b) Condensation
(c) Formation of clouds
(d) Rainwater harvesting

9. Which of the following inhibits the seepage of rainwater into ground?

(a) A pukka floor
(b) playground
(c) Grass lawn
(d) Forest land

10. The cause of depletion of water table is:

(a) increasing industries
(b) water table
(c) rain water
(d) none of these

11. Steam is which form of water?

(a) solid
(b) liquid
(c) gas
(d) none of these

12. Snow and ice, are present as ________ at the poles of the earth, snow-covered mountains, and glaciers.

(a) liquid form
(b) the solid form
(c) the gaseous form
(d) none of the above

13. The solid parts of the earth’s crust called:

(a) atmosphere
(b) lithosphere
(c) hydrosphere
(d) none of these

14. Which of the following is a way to use water economically?

(a) construction of bawris
(b) Rainwater harvesting
(c) Drip irrigation
(d) Infiltration

15. The process of ground water getting stored between the layers of hard rock below the water table is known as

(a) Infiltration
(b) Aquifer
(c) Water table
(d) Bawri

16. River Yamuna is polluted near Delhi due to

(a) Thermal plant on its bank
(b) Water animals
(c) Addition of untreated sewage
(d) Rivers joining it

17. The traditional way of collecting water was:

(a) bawaris
(b) well
(c) rivers
(d) none of these

18. Plants loose water in form of

(a) Liquid
(b) Gases
(c) Snow
(d) Water vapour

19. Main source of water on earth is:

(a) rain
(b) snow
(c) glaciers
(d) all the above

20. The water below the ground is known as

(a) groundwater
(b) pure water
(c) polluted water
(d) none of these

21. Earth appear blue from sky due to presence of

(a) Desert
(b) Mountains
(c) Land
(d) Water

22. The process of seeping of water into the ground is called

(a) Infiltration
(b) Aquifer
(c) Water table
(d) Bawri

23. Water is chlorinated to

(a) Kill germs
(b) Change colour
(c) Soften it
(d) Improve its taste

24. Addition of harmful substance in water leads to

(a) Algal bloom
(b) Microbial growth
(c) High oxygen demand
(d) Water pollution

25. The process of changing water vapour into water is called

(a) Boiling
(b) Condensation
(c) Evaporation
(d) Sedimentation

Answer:

1. Answer: (b) 22nd March

Explanation: World Water Day is an annual United Nations (UN) observance day held on 22 March that highlights the importance of fresh water. The day is used to advocate for the sustainable management of freshwater resources.

2. Answer: (a) 2003

Explanation: Year 2003 was observed as the International Year of Freshwater to make people aware of this dwindling natural resource.

3. Answer: (d) A family gets three buckets of water per person per day

Explanation: Water shortage is the lack of sufficient available water resources to meet the demands of water usage within a region.There seems no water shortage as three buckets of water per person is enough for satisfying their daily needs.

4. Answer: (a) 0.006%

Explanation:The total amount of fresh water available for use is about 0.006% of the total water present on earth as about 97.4% of the total water on earth is in seas and ocean and 2% water is present in the form of glaciers and in polar ice caps.

5. Answer: (c) Drip irrigation

Explanation: One such traditional practice listed above is construction of bawris which is actually constructing deep wells followed by steps made by mud deep in the ground. These bawris would get filled with water whenever there is rain and hence was used by villagers to carry out their daily chores and to collect water.

6. Answer: (d) 50 litres

Explanation: The amount of water recommended by the United Nations for drinking, washing, cooking and maintaining proper hygiene is a minimum of 50 litres per person per day. This amount is about two and a half buckets of water per person per day.

7. Answer: (c) importance of water

Explanation: Every drop counts' is the slogan related to the importance of water. Water is very important for humans as well as for animals. But fresh water is less than one percent of water available on the Earth.

8. Answer: (d) Rainwater harvesting

Explanation: Liquid water evaporates into water vapor, condenses to form clouds, and precipitates back to earth in the form of rain and snow. The water cycle does not involve rainwater harvesting as it is the collection and storage of rain, rather than allowing it to run off.

9. Answer: (a) A pukka floor

Explanation: A pukka floor is a cement floor which is impenetrable to water. Hence water cannot seep through the pukka floor.

10. Answer: (a) increasing industries

Explanation: Every industry requires water in its production process. As a number of industries increases, more water is drawn from the ground. All of this result in depletion of the water table.

11. Answer: (c) gas

Explanation: Steam is water in the gas phase. Steam that is saturated or superheated is invisible; however, "steam" often refers to wet steam, the visible mist or aerosol of water droplets formed as water vapour condenses.

12. Answer: (b) the solid form

Explanation: Water can be found in liquid form in oceans, rivers, lakes and rain; in solid form in ice and snow; and as a gas (water vapour) in the atmosphere.

13. Answer: (b) lithosphere

Explanation:The outermost layer, called the crust, is solid, too. Together, these solid parts are called the lithosphere. Earth's crust is made up of hard rocks.

14. Answer: (c) Drip irrigation

Explanation: Drip irrigation is the method to use water economically. As in drip irrigation system the water is supplied drop by drop to plants which does not cause the wastage of water and supply as per the needs of the plants.

15. Answer: (b) Aquifer

Explanation: An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand or salt). Ground water can be extracted using a water well.

16. Answer: (c) Addition of untreated sewage

Explanation: Essentially, the release of poorly treated or even completely untreated sewage is responsible for the frothing and foaming of the river water. Surfactants and phosphates that originate from detergents used in households and industrial laundries, when released in the river untreated, create the foam.

17. Answer: (a) bawaris

Explanation: Bawri were deep step wells built into the ground. It was the traditional way of rainwater harvesting.

18. Answer: (d) Water vapour

Explanation: Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. Transpiration is essentially evaporation of water from plant leaves.

19. Answer: (a) rain

Explanation: The main source of water is the rainwater. The water cycle is a process that involves evaporation, condensation and precipitation and the output is rainwater. The water source is important in the water cycle.

20. Answer: (a) groundwater

Explanation: Groundwater, water that occurs below the surface of Earth, where it occupies all or part of the void spaces in soils or geologic strata. It is also called subsurface water to distinguish it from surface water, which is found in large bodies like the oceans or lakes or which flows overland in streams.

21. Answer: (d) Water

Explanation: The Earth has been blue for over 4 billion years because of the liquid water on its surface. There is only one known planet with permanent bodies of liquid water at its surface: ours. Earth sciences allow us to explain why the Earth has almost always been blue: it's neither too warm nor too cold.

22. Answer: (a) Infiltration

Explanation: Process of seeping of water into the ground is called infiltration . Infiltration is the process by which bulk of rainwater and melted snow soaks into subsurface soils and moves into rocks through cracks and pores,

23. Answer: (a) Kill germs

Explanation: Water chlorination is the process of adding chlorine or chlorine compounds such as sodium hypochlorite to water. This method is used to kill bacteria, viruses and other microbes in water. In particular, chlorination is used to prevent the spread of waterborne diseases such as cholera, dysentery, and typhoid.

24. Answer: (d) Water pollution

Explanation: The addition of any substance to water, which leads to change in its physical and chemical characteristic, is defined as water pollution.

25. Answer: (b) Condensation

Explanation: The process of changing water vapour into water is called condensation.This is due to the change of gaseous state of water into liquid state. Some common examples of condensation are Formation of drops of water on the outside of a glass of ice water. ,Formation of dew on grass overnight.

Click here for Practice MCQ Questions for Water: A Precious Resource Class 7

Discussion

37.	The refractive index of convex lens material is 1.46. The refractive index of Benzene and water is 1.5 and 1.0 respectively. How does the lens behaves when it is kept in Benzene and water? Given and write.
Answer» 1. When the convex lens with refractive index 1.46 is kept in Benzene with refractive index 1.5, then the lens acts as a diverging lens. 2. If the same lens is kept in water whose refractive index is 1, then it acts as a converging lens.

37.

The refractive index of convex lens material is 1.46. The refractive index of Benzene and water is 1.5 and 1.0 respectively. How does the lens behaves when it is kept in Benzene and water? Given and write.

Answer»

1. When the convex lens with refractive index 1.46 is kept in Benzene with refractive index 1.5, then the lens acts as a diverging lens.

2. If the same lens is kept in water whose refractive index is 1, then it acts as a converging lens.

Discussion

38.	Write the applications of lenses in day to day life.
Answer» Uses of lenses in day to day life : 1. Lenses are used for correcting eye defects. 2. They are used as magnifying lenses. 3. They are used in microscopes, telescopes, binoculars. 4. They are used in cinema projectors and cameras.

38.

Write the applications of lenses in day to day life.

Answer»

Uses of lenses in day to day life :

1. Lenses are used for correcting eye defects.

2. They are used as magnifying lenses.

3. They are used in microscopes, telescopes, binoculars.

4. They are used in cinema projectors and cameras.

Discussion

39.	(a) What do you understand by the term refraction of light? (b) How does the light deviate when it travels from? 1. a rarer to a denser medium 2. a denser to a rarer medium?
Answer» (a) Refraction of light : “When light travels from one optical medium to other optical medium, it changes its path, this change in path is called refraction of light”. (b) (i) Towards the normal, (ii) Away from normal.

39.

(a) What do you understand by the term refraction of light? (b) How does the light deviate when it travels from? 1. a rarer to a denser medium 2. a denser to a rarer medium?

Answer»

(a) Refraction of light : “When light travels from one optical medium to other optical medium, it changes its path, this change in path is called refraction of light”.

(b) (i) Towards the normal, (ii) Away from normal.

Discussion

40.	(a) State the laws of refraction. (b) What do you understand by the statement that refractive index of water is 1.33?
Answer» (a) Laws of refraction : (i) Snell’s law : The ratio between the values of the sine of angle of incidence and the sine of angle of refraction for two given optical media is a constant quantity. µ = sin i / sin r (ii) The incident ray, the refracted ray and the normal lie on the same plane at the point of incidence. (b) Refractive index of water is 1.33 means that speed of light in air is 1.33 times faster than in water.

40.

(a) State the laws of refraction. (b) What do you understand by the statement that refractive index of water is 1.33?

Answer»

(a) Laws of refraction :

(i) Snell’s law : The ratio between the values of the sine of angle of incidence and the sine of angle of refraction for two given optical media is a constant quantity. µ = sin i / sin r

(ii) The incident ray, the refracted ray and the normal lie on the same plane at the point of incidence.

(b) Refractive index of water is 1.33 means that speed of light in air is 1.33 times faster than in water.

Discussion

41.	Write the role of lenses in our daily life.
Answer» The role of lenses in our daily life : 1. Used for correcting eye defects. 2. Used as magnifying lens. 3. Used in Microscopes. 4. Used in Telescopes. 5. Used in Binoculars. 6. Used in Cinema Projectors. 7. Used in Cameras.

41.

Write the role of lenses in our daily life.

Answer»

The role of lenses in our daily life :

1. Used for correcting eye defects.

2. Used as magnifying lens.

3. Used in Microscopes.

4. Used in Telescopes.

5. Used in Binoculars.

6. Used in Cinema Projectors.

7. Used in Cameras.

Discussion

42.	In which of the following case a light ray does not deviate from its path at the interface of two media ?A) It is incident normally B) Refractive indices of two media is same C) It is incident obliquely D) Both A and B
Answer» D) Both A and B

Discussion

43.	State the characteristics of photoelectric effect.
Answer» Characteristics of photoelectric effect: (1) For every metal surface there is a limiting frequency of incident radiation below which no photoelectrons are emitted from that metal surface. This frequency, called the threshold frequency, is characteristic of the metal irradiated. (2) The time rate of emission of photoelectrons in-creases in direct proportion to the intensity, of incident radiation. (3) The photoelectrons have different speeds at the time of emission ranging from zero to a certain maximum value, which is characteristic for a given metal for a given frequency of the incident radiation. The maximum kinetic energy of the photoelectrons at the time of emission is independent of the intensity but increases linearly with the frequency of the incident radiation. (4) For incident radiation of frequency greater than or equal to the threshold frequency for a given metal surface, photoelectric emission from the surface is almost instantaneous, even under extremely weak irradiation.

43.

State the characteristics of photoelectric effect.

Answer»

Characteristics of photoelectric effect:

(1) For every metal surface there is a limiting frequency of incident radiation below which no photoelectrons are emitted from that metal surface. This frequency, called the threshold frequency, is characteristic of the metal irradiated.

(2) The time rate of emission of photoelectrons in-creases in direct proportion to the intensity, of incident radiation.

(3) The photoelectrons have different speeds at the time of emission ranging from zero to a certain maximum value, which is characteristic for a given metal for a given frequency of the incident radiation. The maximum kinetic energy of the photoelectrons at the time of emission is independent of the intensity but increases linearly with the frequency of the incident radiation.

(4) For incident radiation of frequency greater than or equal to the threshold frequency for a given metal surface, photoelectric emission from the surface is almost instantaneous, even under extremely weak irradiation.

Discussion

44.	What is reflection?
Answer» The light rays falling on a surface are returned into the original medium. This phenomenon is called reflection.

Discussion

45.	What is the relation between focal length (f) and radius of curvature (R)?
Answer» The radius of curvature of a spherical mirror is twice to its focal length. ⇒ R = 2f (or) f = R/2 .

45.

What is the relation between focal length (f) and radius of curvature (R)?

Answer»

The radius of curvature of a spherical mirror is twice to its focal length.

⇒ R = 2f (or) f = R/2 .

Discussion

46.	Can we get photoemission with an intense beam of radio waves ? Is photoemission possible at all frequencies ?
Answer» The frequency of the incident radiation and not its intensity is the criterion for photoelectric effect. The lowest frequency of electromagnetic waves that can cause photoemission is about 4.6 × 10¹⁴ Hz (for the alkali metal caesium). Since radio waves have frequencies 1 GHz or lower, they cannot cause photoemission. Only alkali metals are photosensitive to visible light; other metals are photosensitive only to far ultraviolet radiations.

46.

Can we get photoemission with an intense beam of radio waves ? Is photoemission possible at all frequencies ?

Answer»

The frequency of the incident radiation and not its intensity is the criterion for photoelectric effect. The lowest frequency of electromagnetic waves that can cause photoemission is about 4.6 × 10¹⁴ Hz (for the alkali metal caesium). Since radio waves have frequencies 1 GHz or lower, they cannot cause photoemission.

Only alkali metals are photosensitive to visible light; other metals are photosensitive only to far ultraviolet radiations.

Discussion

47.	In what cases does a light ray not deviate at the interface of two media?
Answer» 1. When a light ray incident is perpendicular to the interface of surface, it does not undergo deviation. 2. When a light ray incident is more than critical angle, it does not undergo deviation (refraction) but it undergoes reflection to come back into the original medium.

47.

In what cases does a light ray not deviate at the interface of two media?

Answer»

1. When a light ray incident is perpendicular to the interface of surface, it does not undergo deviation.

2. When a light ray incident is more than critical angle, it does not undergo deviation (refraction) but it undergoes reflection to come back into the original medium.

Discussion

48.	Name the phenomenon involved in the function of optical fibre.
Answer» Total Internal Reflection.

Discussion

49.	What is the relation between focal length and radius of curvature?
Answer» Radius of curvature = 2 x focal length ∴ R = 2f (or) f = R/2.

49.

What is the relation between focal length and radius of curvature?

Answer»

Radius of curvature = 2 x focal length

∴ R = 2f (or) f = R/2.

Discussion

50.	One half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations.
Answer» 1. Every part of a lens forms an image. 2. For formation of image we require only two light rays to converge. 3. Therefore, if the lower half of the lens is covered, it will still form a complete image. 4. However the intensity of the image will be reduced. 5. This can be verified experimentally by observing the image of distant object like tree on a screen, when lower half of the lens covered with a black paper.

50.

One half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations.

Answer»

1. Every part of a lens forms an image.

2. For formation of image we require only two light rays to converge.

3. Therefore, if the lower half of the lens is covered, it will still form a complete image.

4. However the intensity of the image will be reduced.

5. This can be verified experimentally by observing the image of distant object like tree on a screen, when lower half of the lens covered with a black paper.

Discussion

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Class 7 Science MCQ Questions of Water: A Precious Resource with Answers?

The refractive index of convex lens material is 1.46. The refractive index of Benzene and water is 1.5 and 1.0 respectively. How does the lens behaves when it is kept in Benzene and water? Given and write.

Write the applications of lenses in day to day life.

(a) What do you understand by the term refraction of light? (b) How does the light deviate when it travels from? 1. a rarer to a denser medium 2. a denser to a rarer medium?

(a) State the laws of refraction. (b) What do you understand by the statement that refractive index of water is 1.33?

Write the role of lenses in our daily life.

In which of the following case a light ray does not deviate from its path at the interface of two media ?A) It is incident normally B) Refractive indices of two media is same C) It is incident obliquely D) Both A and B

State the characteristics of photoelectric effect.

What is reflection?

What is the relation between focal length (f) and radius of curvature (R)?

Can we get photoemission with an intense beam of radio waves ? Is photoemission possible at all frequencies ?

In what cases does a light ray not deviate at the interface of two media?

Name the phenomenon involved in the function of optical fibre.

What is the relation between focal length and radius of curvature?

One half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations.