13232 + Interview Questions in Physics Page 1 InterviewSolution

1.	Question 24How does the force of attraction between the two bodies depend upon their masses and distance between them? A student thought that two bricks tied together would fall faster than a single one under the action of gravity. Do you agree with his hypothesis or not? Comment.
Answer» Question 24 How does the force of attraction between the two bodies depend upon their masses and distance between them? A student thought that two bricks tied together would fall faster than a single one under the action of gravity. Do you agree with his hypothesis or not? Comment.

Discussion

2.	Question 7 (c) A 8000 kg engine pulls a train of 5 wagons, each of 2000 kg, along a horizontal track. If the engine exerts a force of 40000 N and the track offers a friction force of 5000 N, then calculate: (c) the force of wagon 1 on wagon 2.
Answer» Question 7 (c) A 8000 kg engine pulls a train of 5 wagons, each of 2000 kg, along a horizontal track. If the engine exerts a force of 40000 N and the track offers a friction force of 5000 N, then calculate: (c) the force of wagon 1 on wagon 2.

Discussion

3.	If the linear density of a rod of length L varies as λ = kx where k is a constant and x is the distance of any point from one endplaced at origin. The distance of centre of mass from x = 0 is
Answer» If the linear density of a rod of length L varies as λ = kx where k is a constant and x is the distance of any point from one end placed at origin. The distance of centre of mass from x = 0 is

Discussion

4.	A body sinks when immersed in kerosene. What relation can be established between the density of body and kerosene?
Answer» A body sinks when immersed in kerosene. What relation can be established between the density of body and kerosene?

Discussion

5.	If a person drops a pebble in a well of 100 m depth, after how much time (in seconds) will he be able to hear the sound?Given:Acceleration due to gravity, g=10 ms−2Speed of sound in air, v=343 ms−1
Answer» If a person drops a pebble in a well of $100 m$ depth, after how much time (in seconds) will he be able to hear the sound? Given: Acceleration due to gravity, $g = 10 m s^{- 2}$ Speed of sound in air, $v = 343 m s^{- 1}$

Discussion

6.	The current supplied by the battery in the circuit shown in figure is
Answer» The current supplied by the battery in the circuit shown in figure is

Discussion

7.	The device which use Pascal law is
Answer» The device which use Pascal law is

Discussion

8.	Time period of a sound wave is defined as:
Answer» Time period of a sound wave is defined as:

Discussion

9.	If the density of the water is equal to the density of ship then does it sink or float?
Answer» If the density of the water is equal to the density of ship then does it sink or float?

Discussion

10.	A magnet of length L and magnetic moment M is made into two halves A and B, perpendicular to its axis. One piece A is bent into a semicircle of radius R and is joined to the other piece at the poles as shown in the figure below. Assuming that the magnet is in the form of a thin wire initially .Find the magnetic moment of the resulting magnet.
Answer» A magnet of length $L$ and magnetic moment $M$ is made into two halves $A$ and $B$ , perpendicular to its axis. One piece $A$ is bent into a semicircle of radius $R$ and is joined to the other piece at the poles as shown in the figure below. Assuming that the magnet is in the form of a thin wire initially .Find the magnetic moment of the resulting magnet.

Discussion

11.	State whether the following statement is true or false: Earth moves round the sun with uniform velocity.
Answer» State whether the following statement is true or false: Earth moves round the sun with uniform velocity.

11.

State whether the following statement is true or false: Earth moves round the sun with uniform velocity.

Answer»

State whether the following statement is true or false:

Earth moves round the sun with uniform velocity.

Discussion

12.	What is a refrence point?
Answer» What is a refrence point?

Discussion

13.	A bullet of mass 10 g moving with a speed of20 m/s hits an ice block of mass 990 g kept onfrictionless floor and gets stuck in it. How muchice will melt if 50% of the lost KE goes to ice?finitial temperature of the ice block andbullet 0^° C)
Answer» A bullet of mass 10 g moving with a speed of20 m/s hits an ice block of mass 990 g kept onfrictionless floor and gets stuck in it. How muchice will melt if 50% of the lost KE goes to ice?finitial temperature of the ice block andbullet 0^° C)

Discussion

14.	Deep pond of water has its top layer frozen during winter. State the expected temperature of water layer (i) just in contact with ice, (ii) at the bottom of pond.
Answer» Deep pond of water has its top layer frozen during winter. State the expected temperature of water layer (i) just in contact with ice, (ii) at the bottom of pond.

Discussion

15.	Explain why can echoes not be heard in a small room.
Answer» Explain why can echoes not be heard in a small room.

Discussion

16.	A 10 N force is applied on B. All surfaces are smooth Mass of A & B are 5 kg each. What is the acceleration of A?(A)0 m/s(B) 2 m/s(C)1m/s(D)3 m/s
Answer» A 10 N force is applied on B. All surfaces are smooth Mass of A & B are 5 kg each. What is the acceleration of A?(A)0 m/s(B) 2 m/s(C)1m/s(D)3 m/s

Discussion

17.	a block of ice is floating in aliquid of specific gravity 1.2 contained ina beaker. when thw ice melts completly the level of liquid in the vessel
Answer» a block of ice is floating in aliquid of specific gravity 1.2 contained ina beaker. when thw ice melts completly the level of liquid in the vessel

Discussion

18.	The characteristic property of human ear due to which it cannot distinguish between two sounds when it reaches the ear within 0.1 second is known as ________.
Answer» The characteristic property of human ear due to which it cannot distinguish between two sounds when it reaches the ear within 0.1 second is known as ________.

Discussion

19.	A telescope with objective of focal length 60 cm and eye piece of focal length 5 cm is focused on a far distance object such that the parallel rays emerge from eye piece . If object subtends an angle 2^°on objective, then angular width of the image is
Answer» A telescope with objective of focal length 60 cm and eye piece of focal length 5 cm is focused on a far distance object such that the parallel rays emerge from eye piece . If object subtends an angle 2^°on objective, then angular width of the image is

Discussion

20.	Question 25Two objects of masses m1 and m2 having the same size are dropped simultaneously from heights h1 and h2 respectively. Find out the ratio of time they would take in reaching the ground. Will this ratio remain the same if (i) one of the objects is hollow and the other one is solid and (ii) both of them are hollow, size remaining the same in each case. Give reason.
Answer» Question 25 Two objects of masses $m_{1}$ and $m_{2}$ having the same size are dropped simultaneously from heights $h_{1}$ and $h_{2}$ respectively. Find out the ratio of time they would take in reaching the ground. Will this ratio remain the same if (i) one of the objects is hollow and the other one is solid and (ii) both of them are hollow, size remaining the same in each case. Give reason.

Discussion

21.	Two extreme ends of a moving train (engine and guard coach) pass a pole with speed u and v respectively with a constant acceleration. The speed with which the middle point of the train will pass the same pole is
Answer» Two extreme ends of a moving train (engine and guard coach) pass a pole with speed $u$ and $v$ respectively with a constant acceleration. The speed with which the middle point of the train will pass the same pole is

Discussion

22.	15. Four points masses are placed at the corners of a square of side 2m . Find the centre of mass of the system with respect to the centre of square.Masses are 4kg ,1kg, 2kg , 3kg?
Answer» 15. Four points masses are placed at the corners of a square of side 2m . Find the centre of mass of the system with respect to the centre of square.Masses are 4kg ,1kg, 2kg , 3kg?

Discussion

23.	Question 18Draw a speed versus time graph of a stone thrown vertically upwards and then coming downwards after attaining the maximum height.
Answer» Question 18 Draw a speed versus time graph of a stone thrown vertically upwards and then coming downwards after attaining the maximum height.

Discussion

24.	What is the SI unit of gravitational constant?
Answer» What is the SI unit of gravitational constant?

Discussion

25.	At steady state, find the total charge passed through the cell (6V) & energy lost by cell during this process when connected to a capacitor of 2μ F.
Answer» At steady state, find the total charge passed through the cell (6V) & energy lost by cell during this process when connected to a capacitor of 2μ F.

Discussion

26.	Name the S.I. and C.G.S. unit of force. How are they related?
Answer» Name the S.I. and C.G.S. unit of force. How are they related?

Discussion

27.	A body floats or sinks due to difference in their:
Answer» A body floats or sinks due to difference in their:

Discussion

28.	Question 19In what direction does the buoyant force on an object immersed in a liquid act?
Answer» Question 19 In what direction does the buoyant force on an object immersed in a liquid act?

Discussion

29.	(a) On what factors does the gravitational potential energy of a body depend ? (b) Give one example each of a body possessing : (i) kinetic energy, and (ii) potential energy.
Answer» (a) On what factors does the gravitational potential energy of a body depend ? (b) Give one example each of a body possessing : (i) kinetic energy, and (ii) potential energy.

29.

(a) On what factors does the gravitational potential energy of a body depend ? (b) Give one example each of a body possessing : (i) kinetic energy, and (ii) potential energy.

Answer»

(a) On what factors does the gravitational potential energy of a body depend ?

(b) Give one example each of a body possessing : (i) kinetic energy, and (ii) potential energy.

Discussion

30.	A ball is thrown up vertically returns to the thrower after 6s . Find a. The velocity with which it was thrown up b. The maximum height it reaches. c. It's position after 6s
Answer» A ball is thrown up vertically returns to the thrower after 6s . Find a. The velocity with which it was thrown up b. The maximum height it reaches. c. It's position after 6s

Discussion

31.	A man standing on a cliff claps his hand, and hears its echo after 1 s. If sound is reflected from another mountain and velocity of sound in air is 340 m/s, then the distance between the man and the mountain is
Answer» A man standing on a cliff claps his hand, and hears its echo after $1 s$ . If sound is reflected from another mountain and velocity of sound in air is $340 m/s$ , then the distance between the man and the mountain is

Discussion

32.	The physical quantity, that is generally used to describe how much a body has travelled is __________.
Answer» The physical quantity, that is generally used to describe how much a body has travelled is __________.

Discussion

33.	Three wires of equal lengths are bent in the form of loopsone is circle another is semicircle third is square they are placedin a uniform magnetic field and same electric current is passed through themwhich of them will experience more torque
Answer» Three wires of equal lengths are bent in the form of loops one is circle another is semicircle third is square they are placed in a uniform magnetic field and same electric current is passed through them which of them will experience more torque

Discussion

34.	A certain person has minimum distance of distinct vision of 150 cm. He wishes to read at a distance of 25 cm. What focal length glass should he use? What is the nature of eye defect?
Answer» A certain person has minimum distance of distinct vision of 150 cm. He wishes to read at a distance of 25 cm. What focal length glass should he use? What is the nature of eye defect?

Discussion

35.	The radii of the axle and the wheel are increased by 3 times and 5 times respectively .The new mechanical advantage of the wheel and axle is _
Answer» The radii of the axle and the wheel are increased by 3 times and 5 times respectively .The new mechanical advantage of the wheel and axle is _

Discussion

36.	A car starts from rest . It moves with uniform acceleration. In 10sec it attains a speed of 72km/h on a straight road. Find its acceleration?
Answer» A car starts from rest . It moves with uniform acceleration. In 10sec it attains a speed of 72km/h on a straight road. Find its acceleration?

Discussion

37.	We use Fleming’s right hand rule in which of these cases?
Answer» We use Fleming’s right hand rule in which of these cases?

Discussion

38.	Study the following activity and answer the questions.1. Take two aluminium channels of different lengths.2. Place the lower ends of the channels on the floor and hold their upper ends at the same height.3. Now take two balls of the same size and weight and release them from the top end of the channels. They will roll down and cover the same distance.Questions1. At the moment of releasing the balls, which energy do the balls have?2. As the balls roll down which energy is converted into which other form of energy?3. Why do the balls cover the same distance on rolling down?4. What is the form of the eventual total energy of the balls?5. Which law related to energy does the above activity demonstrate? Explain.
Answer» Study the following activity and answer the questions. 1. Take two aluminium channels of different lengths. 2. Place the lower ends of the channels on the floor and hold their upper ends at the same height. 3. Now take two balls of the same size and weight and release them from the top end of the channels. They will roll down and cover the same distance. Questions 1. At the moment of releasing the balls, which energy do the balls have? 2. As the balls roll down which energy is converted into which other form of energy? 3. Why do the balls cover the same distance on rolling down? 4. What is the form of the eventual total energy of the balls? 5. Which law related to energy does the above activity demonstrate? Explain.

Discussion

39.	Use the following information to answer the next question. A bus accelerates uniformly from 15 m/s to 20 m/s in 6 s. What is the distance covered by the bus during its acceleration?
Answer» Use the following information to answer the next question. A bus accelerates uniformly from 15 m/s to 20 m/s in 6 s. What is the distance covered by the bus during its acceleration?

39.

Use the following information to answer the next question. A bus accelerates uniformly from 15 m/s to 20 m/s in 6 s. What is the distance covered by the bus during its acceleration?

Answer»

Use the following information to answer the next question.

A bus accelerates uniformly from 15 m/s to 20 m/s in 6 s.

What is the distance covered by the bus during its acceleration?

Discussion

40.	How does the resistance of a pure metal change if its temperature decrease ?
Answer» How does the resistance of a pure metal change if its temperature decrease ?

Discussion

41.	can pir sensor detect wind or sun
Answer» can pir sensor detect wind or sun

Discussion

42.	When a body moving with a speed of 20 m/s. stops in 20 seconds, what is the acceleration?
Answer» When a body moving with a speed of 20 m/s. stops in 20 seconds, what is the acceleration?

Discussion

43.	When a carpet is beaten with a stick, dust comes out of it. Explain why this happens?
Answer» When a carpet is beaten with a stick, dust comes out of it. Explain why this happens?

Discussion

44.	A body weighs 100 N on the surface of Earth. What will be the acceleration due to gravity acting on the body at a height of 3400 km above Earth's surface? Taking the mass of Earth=6×1024 kg, Radius of earth=6.4×106 m and G=6.7×10−11 Nm2kg−2.
Answer» A body weighs 100 N on the surface of Earth. What will be the acceleration due to gravity acting on the body at a height of 3400 km above Earth's surface? Taking the mass of Earth $= 6 \times 10^{24} k g$ , Radius of earth $= 6.4 \times 10^{6} m$ and $G = 6.7 \times 10^{- 11} N m^{2} k g^{- 2}$ .

Discussion

45.	Newton's third law: (a) defines the force qualitatively (b) defines the force quantitatively (c) explaines the way the force acts on a body (d) gives the direction of force.
Answer» Newton's third law: (a) defines the force qualitatively (b) defines the force quantitatively (c) explaines the way the force acts on a body (d) gives the direction of force.

Discussion

46.	The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy? Why?
Answer» The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy? Why?

Discussion

47.	a heavy particle hanging from a string of length l is projected horizontally with speed \surd gl.find speed of particle at point where tension in string equals weight of particl
Answer» a heavy particle hanging from a string of length l is projected horizontally with speed \surd gl.find speed of particle at point where tension in string equals weight of particl

Discussion

48.	Q. निम्नलिखित कथनों पर विचार कीजिए: 1. प्रस्तावना में समता, स्वतंत्रता और बंधुत्व के आदर्श फ्रांस की क्रांति से प्रेरित हैं। 2. प्रस्तावना समता के उदेश्य में प्रतिष्ठा, अवसर और वर्गीय सामाजिक व्यवस्था को बनाए रखने को परिलक्षित करती है। उपर्युक्त दिए गए कथनों में से कौन-सा/से कथन सही है/हैं?
Answer» Q. निम्नलिखित कथनों पर विचार कीजिए: 1. प्रस्तावना में समता, स्वतंत्रता और बंधुत्व के आदर्श फ्रांस की क्रांति से प्रेरित हैं। 2. प्रस्तावना समता के उदेश्य में प्रतिष्ठा, अवसर और वर्गीय सामाजिक व्यवस्था को बनाए रखने को परिलक्षित करती है। उपर्युक्त दिए गए कथनों में से कौन-सा/से कथन सही है/हैं?

48.

Q. निम्नलिखित कथनों पर विचार कीजिए: 1. प्रस्तावना में समता, स्वतंत्रता और बंधुत्व के आदर्श फ्रांस की क्रांति से प्रेरित हैं। 2. प्रस्तावना समता के उदेश्य में प्रतिष्ठा, अवसर और वर्गीय सामाजिक व्यवस्था को बनाए रखने को परिलक्षित करती है। उपर्युक्त दिए गए कथनों में से कौन-सा/से कथन सही है/हैं?

Answer»

Q. निम्नलिखित कथनों पर विचार कीजिए:

1. प्रस्तावना में समता, स्वतंत्रता और बंधुत्व के आदर्श फ्रांस की क्रांति से प्रेरित हैं।

2. प्रस्तावना समता के उदेश्य में प्रतिष्ठा, अवसर और वर्गीय सामाजिक व्यवस्था को बनाए रखने को परिलक्षित करती है।

उपर्युक्त दिए गए कथनों में से कौन-सा/से कथन सही है/हैं?

Discussion

49.	A car moving at a constant speed of 54 km/h comes to rest in 2.5 seconds. The car covers 5 m after driver applies the brakes. The total force applied to stop the car is 1000 N. Calculate the power dissipated in stopping the car.
Answer» A car moving at a constant speed of $54 k m / h$ comes to rest in $2.5 s e c o n d s$ . The car covers $5 m$ after driver applies the brakes. The total force applied to stop the car is $1000 N$ . Calculate the power dissipated in stopping the car.

Discussion

50.	If a ball strikes the ground with a force of 3 N, the force exerted by the ground on the ball is
Answer» If a ball strikes the ground with a force of $3 N$ , the force exerted by the ground on the ball is

Discussion

Explore topic-wise InterviewSolutions in .

Question 24How does the force of attraction between the two bodies depend upon their masses and distance between them? A student thought that two bricks tied together would fall faster than a single one under the action of gravity. Do you agree with his hypothesis or not? Comment.

Question 7 (c) A 8000 kg engine pulls a train of 5 wagons, each of 2000 kg, along a horizontal track. If the engine exerts a force of 40000 N and the track offers a friction force of 5000 N, then calculate: (c) the force of wagon 1 on wagon 2.

If the linear density of a rod of length L varies as λ = kx where k is a constant and x is the distance of any point from one endplaced at origin. The distance of centre of mass from x = 0 is

A body sinks when immersed in kerosene. What relation can be established between the density of body and kerosene?

If a person drops a pebble in a well of 100 m depth, after how much time (in seconds) will he be able to hear the sound?Given:Acceleration due to gravity, g=10 ms−2Speed of sound in air, v=343 ms−1

The current supplied by the battery in the circuit shown in figure is

The device which use Pascal law is

Time period of a sound wave is defined as:

If the density of the water is equal to the density of ship then does it sink or float?

State whether the following statement is true or false: Earth moves round the sun with uniform velocity.

What is a refrence point?

A bullet of mass 10 g moving with a speed of20 m/s hits an ice block of mass 990 g kept onfrictionless floor and gets stuck in it. How muchice will melt if 50% of the lost KE goes to ice?finitial temperature of the ice block andbullet 0^° C)

Deep pond of water has its top layer frozen during winter. State the expected temperature of water layer (i) just in contact with ice, (ii) at the bottom of pond.

Explain why can echoes not be heard in a small room.

A 10 N force is applied on B. All surfaces are smooth Mass of A & B are 5 kg each. What is the acceleration of A?(A)0 m/s(B) 2 m/s(C)1m/s(D)3 m/s

a block of ice is floating in aliquid of specific gravity 1.2 contained ina beaker. when thw ice melts completly the level of liquid in the vessel

The characteristic property of human ear due to which it cannot distinguish between two sounds when it reaches the ear within 0.1 second is known as ________.

A telescope with objective of focal length 60 cm and eye piece of focal length 5 cm is focused on a far distance object such that the parallel rays emerge from eye piece . If object subtends an angle 2^°on objective, then angular width of the image is

Two extreme ends of a moving train (engine and guard coach) pass a pole with speed u and v respectively with a constant acceleration. The speed with which the middle point of the train will pass the same pole is

15. Four points masses are placed at the corners of a square of side 2m . Find the centre of mass of the system with respect to the centre of square.Masses are 4kg ,1kg, 2kg , 3kg?

Question 18Draw a speed versus time graph of a stone thrown vertically upwards and then coming downwards after attaining the maximum height.

What is the SI unit of gravitational constant?

At steady state, find the total charge passed through the cell (6V) & energy lost by cell during this process when connected to a capacitor of 2μ F.

Name the S.I. and C.G.S. unit of force. How are they related?

A body floats or sinks due to difference in their:

Question 19In what direction does the buoyant force on an object immersed in a liquid act?

(a) On what factors does the gravitational potential energy of a body depend ? (b) Give one example each of a body possessing : (i) kinetic energy, and (ii) potential energy.

A ball is thrown up vertically returns to the thrower after 6s . Find a. The velocity with which it was thrown up b. The maximum height it reaches. c. It's position after 6s

A man standing on a cliff claps his hand, and hears its echo after 1 s. If sound is reflected from another mountain and velocity of sound in air is 340 m/s, then the distance between the man and the mountain is

The physical quantity, that is generally used to describe how much a body has travelled is __________.

Three wires of equal lengths are bent in the form of loopsone is circle another is semicircle third is square they are placedin a uniform magnetic field and same electric current is passed through themwhich of them will experience more torque

A certain person has minimum distance of distinct vision of 150 cm. He wishes to read at a distance of 25 cm. What focal length glass should he use? What is the nature of eye defect?

The radii of the axle and the wheel are increased by 3 times and 5 times respectively .The new mechanical advantage of the wheel and axle is _

A car starts from rest . It moves with uniform acceleration. In 10sec it attains a speed of 72km/h on a straight road. Find its acceleration?

We use Fleming’s right hand rule in which of these cases?

Use the following information to answer the next question. A bus accelerates uniformly from 15 m/s to 20 m/s in 6 s. What is the distance covered by the bus during its acceleration?

How does the resistance of a pure metal change if its temperature decrease ?

can pir sensor detect wind or sun

When a body moving with a speed of 20 m/s. stops in 20 seconds, what is the acceleration?

When a carpet is beaten with a stick, dust comes out of it. Explain why this happens?

A body weighs 100 N on the surface of Earth. What will be the acceleration due to gravity acting on the body at a height of 3400 km above Earth's surface? Taking the mass of Earth=6×1024 kg, Radius of earth=6.4×106 m and G=6.7×10−11 Nm2kg−2.

Newton's third law: (a) defines the force qualitatively (b) defines the force quantitatively (c) explaines the way the force acts on a body (d) gives the direction of force.

The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy? Why?

a heavy particle hanging from a string of length l is projected horizontally with speed \surd gl.find speed of particle at point where tension in string equals weight of particl

A car moving at a constant speed of 54 km/h comes to rest in 2.5 seconds. The car covers 5 m after driver applies the brakes. The total force applied to stop the car is 1000 N. Calculate the power dissipated in stopping the car.

If a ball strikes the ground with a force of 3 N, the force exerted by the ground on the ball is