InterviewSolution
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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.
| 1851. |
A source producing a sound of frequency 90 Hz is approaching a stationary listener with a speed equal to (1/10) of the speed of sound. What will be the frequency heard by the listener? |
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Answer» Solution :When the SOURCE is MOVING towards the STATIONARY listener, the expression for apparent frequency is `N.=((v)/(v-v_(s)))n` `=((v)/(v-((1)/(10))v))n=((10)/(9))n` `=((10)/(9))xx90=100Hz` |
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| 1852. |
Where does the signal in your cell phone come from? Where from does it come to mobile towers? Where does the signal to your TV set come from ? Youb may have seen photographs showing the position of monsoon clouds over the contry, in the newspaper. How are these images obtained ? |
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Answer» Solution :Mobiles recevie its signal from the nearest MOBILE tower and the mobile towers receive signal through various communication satellite series. Similarly , the TV set RECEIVES the signal coming from various broadcasting satellites revolving around the earth. NEWSPAPERS get the photographs SHOWING the position of monsoon clouds over the country and various weather changes with the help of wearther changes with the help of wearther satellites . For example: INSAT,GSAT series of satellites. |
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| 1853. |
Latent heat of fusion / melting of ice: |
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| 1854. |
Identify from the following reactions the reactants that undergo oxidation and reduction. NiO+H_(2)rarrNi+H_(2)O |
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Answer» Solution :`NiO + H_(2) to NI + H_(2)O` In this REACTION, reduction, of NiO TAKES place and oxidation of `H_(2)` takes place. |
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| 1855. |
Compare and contrast fossil fuels and the sun as direct sources of energy? |
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Answer» Solution : * Fossil fuels are energy sources, such as coal and petroleum, obtained from UNDERNEATH the earth.s crust, they are directly available to human beings for use. Hence, fossil fules are the direct SOURCE of energy These are limited in amount. These are nonrenawable sources of energy because these cannot be replenished in NATURE. Fossil fuels take millions of years for their formation. If the present fossil fuel of the earth gets EXHAUSTED, its formation will take several years. Fossil fuels are also very costly * On the other hand, solar energy is a renewable and direct source of energy. The SUN has been shining for several years and will do so for the next five billion years. Solar energy is available free of cost to all in unlimited amount. It replenishes in the sun itself. |
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| 1857. |
Two conductors A and B of resistances 5 Omega and 10 Omega respectively are first joined in parallel and then in series. In each case the voltage applied is 20 V. (i) Draw the circuit diagram to show the combination of these conducton in each case. (ii) In which combination will the voltage across the conductors A and B be the same ? (iii) In which arrangement will the current through A and B be the same ? (iv) Calculate the equivalent resistance for each arrangement. |
Answer» SOLUTION :(i)  ` <br><img src=) (ii) Voltage across A and B will be same in parallel arrangement.(iii) Current in A and B will be same in series arrangement. (IV) Equivalent resistance in (a) Parallel combination `R_(p) ` `= (R_(1)R_(2))/(R_(1)+R_(2))=(5xx10)/(5+10)=(10)/(3)` =3.33 W (b) Series combination `R_(s)=R_(1)+R_(2)` = 5+10 = 15 W |
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| 1858. |
Is there any application of Ohm's Law in daily life ? |
| Answer» Solution :1. Electrical DEVICE like ELECTRIC bulb, iron box and regulators are some application of Ohm's LAW. | |
| 1859. |
Study the diagram given below and answer the following questions : (i) Name the defect of vision depicted in the diagram. (ii) List two causes of the defect. (iii) Draw a ray diagram for the correction of the above defect using an appropriate lens. |
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Answer» Solution :(i) Hypermetropia. (ii) A focal length of the EYE lens is too LONG. The eyeball becomes too SMALL. (iii) Diagram SHOWING correction. 
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| 1860. |
Due to ………….. Of the eye ball the distance between the lens and retina ………………in hypermetropia. |
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| 1861. |
Aadhaar card, PAN card. Greeting card Credit card. |
| Answer» Solution :GREETING CARD (All others are IMPORTANT cards of personal use). | |
| 1862. |
A stone tied to the end of a string 80 cm long is whirled in a horizontal circle with a constant speed. If the stone makes 14 revolutions in 25 seconds, what is the magnitude and direction of acceleration of the stone ? |
| Answer» SOLUTION :`OMEGA=(88)/(25)"rad s"^(-1), omega=(2PI)/(T)=(2pi N)/(t)` | |
| 1864. |
In the Given diagram, the possible direction of heat energy transformation is |
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Answer» `A larr B, A larr C, B larr C` |
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| 1865. |
The process of coatingthe surface of metal with a thin layerof zinc is called _______ |
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Answer» painting |
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| 1866. |
In dobereiner's triad containing Li, Na, K, if atomic masses of lithium and potassium are 6.9 and 39.1 , then what will be the atomic mass of sodium ? |
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Answer» Solution :The ATOMIC mass of SODIUM is the average of the atomic masses of LI and K i.e, ` ( 6.9 + 39.1)/2 =23` The atomic mass of sodium will be 23. |
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| 1867. |
When Newton's colour disc rotates fast it appears white, Mention the phenomenon related to this? |
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| 1868. |
Define angle of deviation. Why do different components of white light split up into spectrum when it passes through a triangular glass prism? |
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Answer» Solution :The angle between the extended incident ray and the emergent ray is CALLED the angle of deviation. This is because the different COLOURS TRAVEL through a GLASS prism at different SPEEDS. |
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| 1869. |
Mirage or have you seen mirage which is an illusion of water on a hot road or desert. Explain |
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Answer» Solution :(i) A MIRAGE is observed on a hot day in the desert or road. (ii) The air near the hot road or desert surface is hot and hence rarer than the air above. (iii) As HEIGHT increases, the refractive index also increases. (IV) The direction of light rays KEEPS changing due to refraction and APPEARS to be coming from the image of the object on the ground. (v) This is called a mirage. |
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| 1870. |
List out theexternaland internal factors thataffectphotosynthesis. |
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Answer» Solution :(a) External Factors: (1) Light (2) Carbon dioxide (3) Temperature (4) Water (5) Mineral (b) Internal Factors: (1) Pigments (2) Leaf age (3) Accumulation of carbohydrates (4) Hormones (II)Vegetative propagation is the only method of multiplication in PLANTS like bana seedless grapes and ORANGE that have lost their capacity to produce seeds through sexual reproduction and vegetative propagation helps us to introduce plants in new areas where seed germination fails to produce plants. |
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| 1871. |
What are thedisadvantges of DC ? |
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Answer» Solution :DISADVANTAGEOF DC areas follows : (1) Relative to THEPRODUCTION of AC, the production of DC is comparatively difficult andexpensive . (2) There is a lotof loss electricityin transmitting Dc over LONG distances. (3) Desired DC voltage / currentcannot be CONTROLLED without singnificant loss of electricity(electric ENERGY ). |
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| 1872. |
Rare species : Musk deer : : ……. : Lesser florican |
| Answer» SOLUTION :ENDANGERED SPECIES | |
| 1873. |
Define accommodation of an eye . |
| Answer» SOLUTION :The ABILITY of the eye to FOCUS both near and distant objects, by adjusting the focallength :is CALLED the accommodation of the eye or the ability of the ciliary MUSCLES to change accormnodation | |
| 1874. |
Out of rods and cones in the retina of your eye : (a) which detect colour ? (b) which work in dim light ? |
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| 1875. |
An image of the same size of an object is formed in a convex lens. Where is the object situated and where is the image formed ? |
| Answer» SOLUTION :At 2F i.e., `|U| = |V| = 2f`. | |
| 1876. |
Sound travels faster in |
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Answer» water |
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| 1877. |
What is the nature of the image formed on the retina? |
| Answer» SOLUTION :REAL, INVERTED and same-sized. | |
| 1878. |
One MeV of nuclear energy is equivalent to : |
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Answer» `1.6 xx 10^(-13) J` |
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| 1879. |
Describlethe construction and working of an electric motor (DC moto) withthe help of a diagram . |
Answer» SOLUTION :CONSTRUCTION: The construction of an ELECTRICIS as SHOWN INFIGURE 13.24. 
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| 1880. |
Calorific value and ignition temperature of fuel X are 75 kJ/g and 20^(@)C respectively. These values for fuel Y are 50 kJ/g and 75^(@)C respectively. On burning, the fuel Y produces only CO_(2) while fuel X produces CO_(2) and CO. Which of the two is a better fuel ? Give two reasons to support your answer. |
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| 1881. |
What is the minimum number of rays required for locating the image formed by a concave mirror for an object. Draw a ray diagram to show the formation of a virtual image by a concave mirror. |
Answer» Solution :A minimum of two rays are required for LOCATING the image formed by a CONCAVE mirror for an object. When the object AB is held between POLE P and principal focus F of the concave mirror, the image formed, A'B' is virtual, erect and magnified as 
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| 1883. |
Wecouldobservepathof lightdueto __ oflightfromtiny particlesof solutionoftransparent medium . |
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Answer» SCATTERING |
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| 1884. |
The building in which you are residing has caught fire on the ground floor. What necessary rescue steps will you take ? |
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Answer» SOLUTION :We shall take the following steps : (1) If there is a fire on the ground FLOOR, it is risky to run out of the building . Therefore, fire brigade will be immediately called to extinguish the fire. (2) Alert all the people by calling them loudly and asking them to take necessary MEASURES. (3) The wet cloth will be used to cover nose and mouth so that the SMOKE and fumes will not cause suffocation. (4) Using alternative way to VACATE the building and then helping others for putting off the fire. (5) First aid will be administered to thevictims. |
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| 1885. |
The force of gravitation is inversely related to _____________. |
| Answer» SOLUTION :SQUAREOF DISTANCEBETWEEN MASSES | |
| 1886. |
The focal length of a camera lens is 20 cm. find how far away from the film must the lens ve set in order to photograph an object located at a distance 100 cm from the lesn . |
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Answer» Solution :GIVEN: Focal length = 20 cm (covex LENS ) Object DISTANCE = 100 cm To find: Image distance (v) Solution : `1/v - 1/u = 1/f ` `1/v - 1/((-100)) = 1/20` `1/v + 1/100 = 1/20 ` `1/v = 1/20 - 1/100` ` 1/v = (5-1)/(100)` `1/v = 4/100` `1/v = 1/25` `therefore` Image distance (v) = 25 cm. |
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| 1887. |
a. An object is kept at a distance of 18 cm, 20 cm, 22 cm and 30cm, from a lens of power + 5D. (i) In which case or cases would you get a magnified image? (ii) Which of the magnified image can we get on a screen? ( b) List two widely used applications of a convex lens. |
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Answer» SOLUTION :a (i) `P=1/f,f=100/5=20cm` Object at 18 cm, 22 cm and 30 cm, IMAGE can be magnified. (II) At 22 cm and 30 cm, image canbe obtained on a screen. b. Film projectors and TELESCOPES. |
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| 1888. |
When a light ray passes obliquely through the atmosphere in an upward direction, how does itspath generally change? |
| Answer» SOLUTION :LIGHT will bend away from its NORMAL direction. | |
| 1889. |
Define electromagneticinduction. |
| Answer» SOLUTION :ELECTROMAGNETIC INDUCTION : The process by which a change in MAGNETIC field in a conductor induces a current in ANOTHER conductor. | |
| 1891. |
Derive the relation between 'g' and G. Explain how to determine the mass of earth. |
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Answer» Solution :(i) Let us COMPUTE the magnitude of this force in two ways. Let, M be the mass of the Earth and m be the mass of the body. (ii) The entire mass of the Earth is assumed to be concentrated at its CENTRE. (iii) The radius of the Earth is `"R = 6378 km ( = 6400 km approximately)"`. By Newton.s law of gravitation, the force ACTING on the body is given by `F=(GMm)/(R^(2))"...(1)"`  (iv) The radius of the body considered is negligible when compared with the Earth.s radius. Now, the same force can be obtained from Newton.s second law of motion. (v) According to this law, the force acting on the body is given by the product of its mass and acceleration (called as weight). Here, acceleration of the body is under the action of gravity hence `a=g` `F= ma = mg` `F="weight"=mg"...(2)"` Comparing EQUATIONS `J=Fxxt and DeltaP=Fxxt`, we get `mg=(GMm)/(R^(2))"...(3)"` Acceleration DUE to gravity `g=(GMm)/(R^(2))"....(4)"` Mass of the Earth (M) : Rearranging the equation (4), the mass of the Earth is obtained as follows : Mass of the Earth `M=gR^(2)//G` Substituting the known values of g, R and G, you can calculate the mass of the Earth as `M=5.972xx10^(24)kg` |
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| 1892. |
Dobereiner arranged the elements in the order of increasing atomic masses in a triad. The arrangement was modified by John Newlands and later by Dimitri Mendeleev. Even Mendeleev's arrangement was later modified by Henry Moseley resulting in the Modern Periodic Table. There are many other similar examples in the history of scientific advancement where theories and novels were modified by later scientists and the original contributors accepted these modifications happily . Answer the following questions asked on the above information: (i) How does the Modern Periodic Law given by Moseley different from Periodic Law stated by Mendeleev? (ii) What scientific values can be associated with the above ancedotes? (iii) Give an example from your life experiences so far that reflects display of such values by you. |
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Answer» Solution :(i) Mendeleev's Periodic Law states that the PROPERTIES of elements are the periodic function of their atomic masses. Mosley's Modern Periodic Law states that the properties of elements are the periodic function of their atomic numbers. (ii) Open-mindedness, ability to ACCEPT failure, intellectual, HONESTY, respect for other's views, spirit of ENQUIRY. (iii) Acceptance of wrong traditional beliefs initially and CHANGE in these beliefs at a later stage. |
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| 1893. |
Define refraction of light. State Snell's law of refraction of light. |
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Answer» Solution :The bending of light when it travels from one medium to another of different optical density is called refraction of light. There are two laws of refraction of light : (i) The incident ray, the normal and the refracted ray, all LIE in the same PLANE. (II) If the ray goes from an optically rarer medium to an optically denser medium, it bends towards normal. However if the ray goes from an optically denser medium (glass) to an optically rarer medium (air), it bends away from the normal. (iii) Ratio of sine of angle of incidence to sine of angle of refraction is CONSTANT i.e. `sini/sinr=a` constant. When .n. is the refractive index of second medium with respect to first medium. This law is also known as Snell.s law of refraction. |
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| 1894. |
Describe an activity with a neat diagram to demonstrate the presence of magnetic field around a current-carrying straight conductor. |
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Answer» Solution :Take a long straight thick copper wire and insert it through the centre of a plane cardboard. Cardboard is fixed so that it is perfectly horizontal and the thick wire is in VERTICAL DIRECTION. Prepare an electric circuit consisting of a battery, a variable resistance, an ammeter and a plug key. Connect the copper wire in the circuit between the points X and Y. Sprinkle some iron-filings uniformly on the cardboard. Put the plug in key K so that a current flows in the circuit. Gently tap the cardboard using a finger. We observe thatthe iron-filings ALIGN themselves forming a pattern of concentric circles around the copper wire. These concentric circles represent the magnetic field lines. Direction of field lines is DETERMINED by the use of a compass needle. If current is flowing vertically downward then the magnetic field lines are along CLOCKWISE direction. If current is flowing vertically upward then the field lines are along anticlockwise direction. 
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| 1895. |
An air conditioner of 2kW is used in an electric circuit having a fuse of 10A rating. If the potential difference of the supply is 220 V will the fuse be able to withstand, when the air conditioner is switched on ? Justify your answer. |
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Answer» <P> SOLUTION :Here P = 2k W = 2000 W, V = 220 VoltP = VI, the current I = `(p)/(V) = (2000)/(220) = 9.09 ` A As the current is 9.09 A, below the rating of fuse, the fuse will withstand i.e., it will not blow off when AC is on. |
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| 1896. |
State the law of refraction of light that defines the refractive index of a medium with respect to the other. Express it mathematically. How is refractive index of any medium A with respect to a medium B relate to the speed of propagation of light in two media A and B ? State the name of this constant when one medium is vacuum or air ? The refractive indices of glass and water with respect to vacuum are (3)/(2) and (4)/(3) respectively. If the speed of light in glass is 2 xx 10^(8) ms^(-1), find the speed of light in (i) vacuum, (ii) water. |
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Answer» Solution :Snell.s law defines the refractive index of a medium with respect to the other. For its statement and mathematical expression, see Point Number 21 under the heading "Chapter At A Glance". Refractive index of a medium A with respect to a medium B `(n_(AB))` `= ("Speed of light in medium B" (v_(B)))/("Speed of light in medium A" (v_(A)))` If ONE medium is AIR or vacuum then this constant is known as the (absolute) refractive index of the other medium. Thus, Refractive index of a medium (n) `= ("Speed of light in vacuum/air (c)")/("Speed of light in the medium (v)")` As per question `n_(g) = (3)/(2) and n_(W) = 2 xx 10^(8) ms^(-1) and v_(g) = 2 xx 10^(8) ms^(-1)` (i) `because n_(g) = (c)/(v_(g))` hence speed of light in vacuum `= n_(g).v_(g) = (3)/(2) xx 2 xx 10^(8) = 3 xx 10^(8) ms^(-1)` (II) Speed of light in water `v_(w) = (c)/(n_(w)) = (3 xx 10^(8))/(4//3) = 2.25 xx 10^(8) ms^(-1)` |
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| 1897. |
An object 5.0 cm in length is placed at a distance of 20 cm in front of a convex mirror of radius of curgature 30 cm. Find the position of the image, its nature and size. |
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Answer» Solution :`h_(1)=-5CM, U--20cm, R=30cm` `v=?,h_(2)=?` `f=R/2=30/2=15cm` `1/f=1/v+1/u` `v=(UF)/(u-f)=(-300)/(-35)` `v=60/7=8.57cm` `m=(h_(2))/(h_(1))=-v/u` `h_(2)=15/7=2.14cm` |
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| 1898. |
The unit of conductance is ____________. |
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Answer» `"OHM"^(-1)` |
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| 1899. |
The apparent depth of a liquid in a vessel is 15 cm, when its real depth is 20 cm. find the refractive index of the liquid. |
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Answer» Solution :Given, REAL DEPTH=20 cm, apparent depth=15 cm. Refractive index of the liquid`=("real depth")/("apparent depth")` `=(20)/(15)=1*33` |
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| 1900. |
Arrange the fuels in the order of Increasing calorific value: LPG, Cowdung cakes, Petrol, Coal, Hydrogen gas. |
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Answer» Coal , COWDUNG CAKES, Petrol, LPG , Hydrogen |
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