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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 751. |
Which of the following cannot be usedfor measuring time in a spaceship orbiting around the earth ? |
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Answer» quartz watch |
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| 752. |
What is the cause of dispersion of light on passing through a prism? |
| Answer» SOLUTION :The REFRACTIVE index of the material of a prism is DIFFERENT for different colours of light as different colours have different speed in the material of a prism. Also, prism has non-parallel surfaces. | |
| 753. |
An electric lamp is labelled 12 V, 36 W. This indicate that it should be used with a 12 V supply. What other information does the label provide? |
| Answer» SOLUTION :The electric LAMP CONSUMES electric ENERGY at the RATE of 36 J/s. | |
| 754. |
Hydrogen has been used as a rocket fuel . Would you consider it a cleaner fuel than CNG ? Why or why not ? |
| Answer» Solution :Hydrogen is a CLEANER fuel than CNG because the burning of hydrogen produces only water, which is completely harmless. The burning of CNG produces carbon dioxide and water . This `CO_2` can PRODUCE greenhouse effect in the atmosphere and lead to the excessive of the ENVIRONMENT in THELONG- run. | |
| 755. |
It is desired to obtain an erect image of an object, using concave mirror of focal length of 12 cm. (i) What should be the range of distance of an object placed in front of the mirror ? (ii) Will the image be smaller or larger than the object ? Draw ray diagram to show the formation of image in this case. (iii) Where will the image of this object be, if it is placed 24 cm in front of the mirror ? Draw ray diagram for this situatioon also to justify your answer. |
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Answer» Solution :It is given that focal length of concave MIRROR is 12 cm. (i) To obtain and erect image of an object by this mirror, the object should be placed in front of the mirror between its pole and focus point, that is `|u| lt 12` cm. (ii) The image is larger than the object. The ray diagram has been shown in Figure. (iii) If object be placed at 24 cm in front of the mirror then it means that the object is situated at the CENTRE of curvature `[because |u| = 24 cm = 2f = 2 xx 12 cm = R]` C of the given mirror. Hence as shown in Figure. The real, inverted image of same size is FORMED at centre of curvature C itself `[|v| = 24 cm]` |
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| 756. |
Use the data in table 12.2 to answer the following: (a) Which among iron and mercury is a better conductor? (b) Which material is the best conductor? |
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Answer» SOLUTION :a) Iron is a better conductor than MERCURY because resistivity of iron is less than that of mercury. (b)Silver is the best conductor because its resistivity is the LEAST. |
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| 757. |
When a light ray passes obliquelly from an optically denser medium to an optically rarer medium, the ray bends away from the normal drawn on the refracting surface at the point of incidence. |
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Answer» |
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| 758. |
Draw a neat labelled diagram : Structure of PSLV made by ISRO. |
Answer» SOLUTION :
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| 759. |
Two carnot engines A and B are operated in series. The first one A receives heat at 900 K and reject to a reservoir at temperature T K. The second engine B receives the heat rejected by the first engine and in turn rejects to a heat reservoir at 400 K calculate the temperature T when (i) The efficiencies of the two engines are equal (ii) The work output of the two engines are equal |
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Answer» Solution :`W_A=W_B` `W/Q_1=(1-(T_2)/(T_1))` `W=Q_1(1-T_2//T_1)` `Q_2(1-(T_3)/T_2)=Q_1(1-T_2/T_1)` `(1-T/(900))Q_1 = (1-(400)/T)Q_2` `(1-T/900)Q_1=(1-(4000)/T)T/900` `1-T/900=T/900-400/900` `(2T)/900=13/9` `T = 650 K` `eta_A=eta_B` `1-T/900=(1-400)/T` `T^2=900xx400` `=600k` `T_1=273k, T_2=673k` MASS of gas = 10 MOLE `W_(adia)=(10R)/((gamma-1))(T_1-T_2)` `=(10xx8.4)/((1.4-1))(273-673)` `=-8.4 xx10^(4)J` work being done on the gas `DU = -DW = 8.4 xx10^(4)J` |
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| 760. |
Define the principal focus of a convace mirror. |
| Answer» SOLUTION :The point on the principal axis where all the light RAYS COMING PARALEL to the principal axis meet after reflection from the mirror is known as principal focus of the CONCAVE mirror. | |
| 761. |
Activity: Put a slab of ice on a stand as shown in the figure below. |
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Answer» Solution : OBSERVATION: The wire GRADUALLY PENETRATES the ice slab and comes out of LOWER surface of the slab after some time without BREAKING the slab. |
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| 762. |
Define biodivesity. |
| Answer» Solution :BIODIVERSITY is the RICHNESS of living organisms in nature DUE to the presence of varieties of organisms, ecosystem and genetic vaiations WITHING a species. | |
| 763. |
In the uncontrolled chain reaction, the numberof __________ multiplies indefinitely. |
| Answer» SOLUTION :NEUTRONS | |
| 764. |
What happensto the image distance in the eye have increase the distance of an object fromthe eye'? |
| Answer» SOLUTION :The SIZE of the EYE can CHANGE, so the imagedistancl is FIXED | |
| 766. |
Unit of electric power may also be expressed as : |
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Answer» <P>volt - ampere |
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| 767. |
A body of mass M at rest is struck by a moving body of mass. Prove that the fraction of the initial kinetic energy of mass transferred to the struck body is (4Mm)/((m+M)^(2)) |
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Answer» SOLUTION :30% of power `=W/t=(MGH)/t=(V rho gh)/t` `30/100xP=(V rho gh)/t` `:.P=43.6KW` |
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| 768. |
Three lenses having powers 2 D,2.5 D and 1.7 D are kept touching in a row. What is the total power of the lens combination ? |
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Answer» <P> To find: Power of COMBINATION (P) Formula: `P=P_(1)+P_(2)+P_(3)` CALCULATION: From formula, `P=2+2.5+1.7=6.2 D` |
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| 769. |
What is meant by the dispersion of white light ? Draw a neat diagram to show dispersion of white light by a glass prism. What is the cause of dispersion ? |
Answer» Solution :Whena beam of white light passes through a glass prism it SPLITS up into its constituent SEVEN colours. The splitting of white light into its constituent colours when light passes through a dispersive medium is called "dispersion of light". The seven colours, usually expressed as VIBGYOR" constitute the spectrum of whitelight.  The ray diagram SHOWING dispersion is GIVEN here. Cause of Dispersion: When a beam of white light enters a glass prism (or any other dispersive medium), the light ray bends towards the normal on entering into glass. However, different colours of light bend through diferent angles with respect to the incident ray. The red light bends the least while the violet light bends the most. So, rays of different colours emerge along different PATHS and, thus, become distinct. Hence, dispersion is caused and spectrum is formed. |
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| 770. |
If both the mass and radius of the earth, each decreases by 50%, the acceleration due to gravity would |
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Answer» REMAINS same |
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| 771. |
Choose the corret option : A rectangular coil of copper wires is rotatedin a magneticfield . The directionof theinduced currentchanges once in each …… |
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Answer» two ROTATIONS |
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| 772. |
A copper block of 3.1 kg is heated in a furnace from 20^@ C " to " 520 ^@Cand then placed on thick ice block. Calculate specific heat of copper if mass of ice melted is 1.8 kg. (Given: Latent heat of fusion of ice = 333 kJ/kg) |
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Answer» SOLUTION :Mass of copper BLOCK `(m_c)=3.1 kg.` Change in temperature `(DeltaT)` = 520 -20 `= 500^@C` Mass of icemethod `(m_("ICE")= 1.8 kg)` |
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| 774. |
How can you appreciate the technology of making ships float, using the material which sink in water ? |
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Answer» Solution :1. we know that a piece of iron sinks in water. 2. The relative density of iron is 8.5 which is many times more than water. 3. A ship that floats on water is made up tonnes of iron. It is really wonderful. 4. ACCORDING to the Archimedes principle of buoyancy any object can float when its weight is equal to the weight of water DISPLACED by it. 5. Hence ships are made with a larger surface area so that it displaces the water, WHOSE weight is equal to the weight of loaded ship. 6. It involves very sharp scientific calculations and a large engineering technology. 7. Really such type of TECHNOLOGIES are highly appreciable and the scientists who formulates all these are also really great. |
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| 775. |
Can you draw a graph between angle of incidence and angle of deviation ? |
| Answer» SOLUTION :YES, we can draw the GRAPH between angle of INCIDENCE and angle of deviation. | |
| 776. |
(i) Neeta needs a lens of power - 4.5D for correction of her vision. (a) What kind of defect in vision is she suffering from ? (b) What is the focal length and nature of corrective lens ? (c) Explain with the help of a diagram how this defect can be corrected ? (ii) State the functions of each of the following parts of human eye. (a) Cornea (b) Pupil(c) Iris(d) Retina |
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Answer» Solution :(a) MYOPIA or NEARSIGHTEDNESS (b) `f = 1//D,` so, `f = -1//45 = (-0.22 m)`, CONCAVE LENS |
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| 777. |
The walls of the halls build for music concerts should_______ sound. |
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Answer» amplify |
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| 778. |
When electrons are removed from an uncharged body, the body |
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Answer» gets negatively CHARGED |
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| 779. |
Your sister has become incommunicative she prefers to remain alone. |
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Answer» Solution :The INDIVIDUAL who PREFERS to be incommunicative has lots of thoughts in his/her mind If his is the case with sister, she will be taken into confidence and the reason behind this lack of communication will be found out. Most often such persons have depression.so she will not be left alone, Her friends will be INVITED at HOME, so that she can converse with them, She should be encouraged to PURSUE her hobbies, She should be helped in selectiong such work, If nothing changes her then the help of counsellor should be taken. |
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| 780. |
The weakest force of interaction is |
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Answer» ELECTROSTATIC |
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| 781. |
Light can travel in a vaccum but not sound because ........... |
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Answer» speed of sound is very slow than LIGHT. |
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| 782. |
A strip of copper was placed in a beaker containing zinc sulphate solution. On observing the strip next day, was there any colour change in the strip? |
| Answer» Solution :On the NEXT day, the copper strip remained as it was because ZINC is more REACTIVE than copper. So, copper was unable to displace zinc from its solution. | |
| 783. |
Can an electron be obtained (or come out ) from the nucleus ? |
| Answer» Solution :Yes, electron having energy HIGHER than the ordinary atomic electron may COME out of the nucleus due to beta decay process. A NEGATIVE beta is identical to an electron in all respect except with difference in KINETIC energy. | |
| 784. |
In practice the unit kWh is used for the measurement of electrical energy, rather than joule. |
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Answer» Solution :i ELECTRICAL energy = Electrical power `xx` time. ii. For practical APPLICATIONS, devices consuming high electrical power are used over the period of time. III. This leads to heavy expenditure of electrical energy. To MEASURE such value of energy unit joule is significantly small. iv. Hence, unit kWh is used in practice. Unit 1 kWh represents power of 1 kW used for 1 hour and EQUALS `3.6 xx 10^(6) J`. |
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| 785. |
Distinguish real and ideal gases. |
Answer» SOLUTION :
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| 786. |
The phenomenon of splitting of light into its component colours is………... |
| Answer» SOLUTION :DISPERSION | |
| 787. |
Electric current is flowing in a conductor. Can we say the conductor is charged ? |
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Answer» Solution :No. In a conductor, the number of POSITIVE charges equals the number of negative charges. Hence, a conductor is electricallyneutal. When an electric flows through a conductor, the number of electrons entering at ONE END of the conductor from the external battery is equal to the number of electrons leaving from the other end of the conductor. In this way the number of electrons remains CONSTANT in the conductor. Thus, when a current flows in a conductorit is not charged. |
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| 789. |
State the rule to determine the direction of a (i) magnetic field produced around a straight conductor- carrying current, (ii) force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it and (iii) current induced in a coil due to its rotation in a magnetic field. |
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Answer» SOLUTION :(i) Right HAND thumb rule (ii) Flemings.s LEFT hand rule (iii) Fleming.s right hand rule |
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| 790. |
A 5 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 20 cm. The distance of the object from the lens is 30 cm. Find the (i) position, (ii) nature, and (iii) size of the image formed. |
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Answer» Solution :Here H = +5 CM, f = +20 cm, u = - 30 cm (i) Using lens FORMULA `(1)/(v) - (1)/(u) = (1)/(f)`, we have `(1)/(v) = (1)/(f) + (1)/(u) = (1)/((20)) + (1)/((-30))= (3-2)/(60) = (1)/(60)` `therefore` v = + 60 cm (ii) +ve sign of v means that image is being formed on the other side of lens i.e., the image is a real image. (iii) As `m = (h.)/(h) = (v)/(u)` `therefore""h. = (v)/(u) . h = ((+60))/((-30)) xx (+5) = - 10` cm |
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| 791. |
When radiation from the sun enters the Earth its value is ___________ per unit area in unit time. |
| Answer» SOLUTION :1.4 KILO JOULE | |
| 792. |
Using a flow chart , explanin the various stages of energy generation using wind energy. |
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Answer» Solution :(i) Electricity generation using wind energy is done with the help of a wind turbine. (ii) A wind turbine is a machine used to convert the KINETIC energy of the wind to electrical energy. (III) A wind turbine consists of rotating blades, a gear box and a generator. (iv) When the wind strikes the blade of the turbine, the blades rotate. (v) The axle of the turbine is connected to the ELECTRIC generator through a gear-box. (vi) The gear-box is used to increase the rotations per unit time. (vii) In this way the rotating blades RUN the turbine which in turn DRIVES the generator to produce electricity. 
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| 793. |
What causes movement of food inside the alimentary canal ? |
| Answer» SOLUTION :When we SWALLOW the food, it is further pushed forward by rhythmic contraction and RELAXATION of muscles present in LINING of alimentary canal.These MOVEMENTS are called peristaltic movements. | |
| 794. |
1. Which property of light can be studied with this procedure? 2. Describe the property in minimum words. 3 What do you obseve? Why does it happen? |
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Answer» Solution :Refraction of light can be studied with this PROCEDURE. 2.The light rays coming from the immersed partof the pencilmove from water to AIR i.e from denser to rarer MEDIUM. These light rays refract at the surface of the water and bend away from normal AS RESULT , these rays appear to come form points which are above the actual points. Therefore the pencil appears to be broken near the surface of water . 
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| 795. |
Identify the various aspects of disaster management based on the given statements. i. Plan for minimizing the damage to the society and country. ii. Intensity of various aspects of disaster and disaster management are reviewed. iii. A plan is chalked out so as to get the quick response from general public and administration. iv. It is an important link between emergency measures and national progress. v. Response to the disaster given immediately vi. Important link between measures after disaster and national development. |
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Answer» Solution :i. Redemptionn ii. IMPACT of DISASTER iii. PREPAREDNESS iv. Resurgence v. Response VI. RESTORATION. |
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| 796. |
Two concave lenses, eacb of focal length 30 cm are placed in contact with each other. Find the power of the combination. |
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Answer» <P> To find: Power of combination (P) FORMULA: `P=(1)/(f)=(1)/(f_(1))+(1)/(f_(2))` Calculation: From formula, `P=(1)/(-0.3)+(1)/(0.3)=(-10)/(3)+(-10)/(3)` `=(-20)/(3)=-6.7 D` |
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| 797. |
Whether there are any changes in nature before the occurrence of disasters? |
| Answer» Solution :Very dry and hot climate, lack of RAINFALL, drying of water resources are the CHANGES seen in NATURE before OCCURRENCE of these DISASTERS. | |
| 798. |
Why do we have to bring a small object near the eyes in order to see it clearly. |
| Answer» SOLUTION :If we bring small objects near the eyes, the angle SUBTENDED by the OBJECT at the eye becomes large which makes the eye to see the object clearly. | |
| 799. |
At what position the object be placed in front of a concave mirror to form a real image of the same size ? |
| Answer» SOLUTION :At the CENTRE of CURVATURE (or at 2F). | |
| 800. |
What is the height of air column which will produce a pressure of 1 atm? Density of air is 1.3 kg/m^3. |
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Answer» 6.45 km |
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