9478 + Interview Questions in Physics Page 1 InterviewSolution

1.	suppose there is a point object in front of a plane mirror. one incident ray from this point strikes mirror and reflect. Another light ray comes from some height which is above than the pointed object, strike the mirror and reflect. but when we extend first and second reflected ray it intersect at a point. will the image of the pointed object will form there. if not, why.
Answer» suppose there is a point object in front of a plane mirror. one incident ray from this point strikes mirror and reflect. Another light ray comes from some height which is above than the pointed object, strike the mirror and reflect. but when we extend first and second reflected ray it intersect at a point. will the image of the pointed object will form there. if not, why.

Discussion

2.	2.When the velocity of a relativistic charged particle increases. It's specific charge
Answer» 2.When the velocity of a relativistic charged particle increases. It's specific charge

Discussion

3.	Two concentric conducting thin spherical shells A and B having radii rA and rB(rB>rA) are charged with charges QA and −QB (\|QB\|>\|QA\|). The electric field along a line, (passing through the centre) varies with distance x from the centre as
Answer» Two concentric conducting thin spherical shells $A$ and $B$ having radii $r_{A}$ and $r_{B}$ $(r_{B} > r_{A})$ are charged with charges $Q_{A}$ and $- Q_{B}$ $(\| Q_{B} \| > \| Q_{A} \|)$ . The electric field along a line, (passing through the centre) varies with distance $x$ from the centre as

Discussion

4.	Wet clothes dry more quickly on a warm dry day than on a cold humid day. Explain.
Answer» Wet clothes dry more quickly on a warm dry day than on a cold humid day. Explain.

Discussion

5.	Write a paragraph on the birth and lifecycle of stars using figure 20.1.
Answer» Write a paragraph on the birth and lifecycle of stars using figure 20.1.

Discussion

6.	Pure water is kept in a container and electricity is passed through it. The level of water in the container ____.
Answer» Pure water is kept in a container and electricity is passed through it. The level of water in the container ____.

Discussion

7.	The phase transition in which a liquid turns into a solid is called as _______
Answer» The phase transition in which a liquid turns into a solid is called as _______

Discussion

8.	Question 10Ultrasound has frequency of vibration(a) Between 20 and 20,000 Hz(b) Below 20 Hz(c) Above 20,000 Hz(d) Between 500 and 10,000 Hz
Answer» Question 10 Ultrasound has frequency of vibration (a) Between 20 and 20,000 Hz (b) Below 20 Hz (c) Above 20,000 Hz (d) Between 500 and 10,000 Hz

Discussion

9.	when one mole of monoatomic gas is mixed with one mole of triatomic gas,then the equivalent value of g for the mixture will be(vibration mode neglected)
Answer» when one mole of monoatomic gas is mixed with one mole of triatomic gas,then the equivalent value of g for the mixture will be(vibration mode neglected)

Discussion

10.	A ball of glass bounces higher than a ball of rubber. Why so?
Answer» A ball of glass bounces higher than a ball of rubber. Why so?

Discussion

11.	73. Why is the potential difference across any one of the resistors in series is directly proportional to resistance ??(But V is inversely proportional to R)
Answer» 73. Why is the potential difference across any one of the resistors in series is directly proportional to resistance ??(But V is inversely proportional to R)

Discussion

12.	How many times more intense is 90 dB sound than 40 dB sound?
Answer» How many times more intense is $90 dB$ sound than $40 dB$ sound?

Discussion

13.	Question 1In which of these mediums can sound travel?(i) Wood(ii) Water(iii) Air(iv) Vacuum
Answer» Question 1 In which of these mediums can sound travel? (i) Wood (ii) Water (iii) Air (iv) Vacuum

Discussion

14.	Mass × change in velocity = ___ × time interval.
Answer» Mass $\times$ change in velocity = ___ $\times$ time interval.

Discussion

15.	A concave mirtor is hait dpped in water Focal length of portion of mirror is the air is f, and focal length ofmeror in water is then (Take neltractive index of water5/3)
Answer» A concave mirtor is hait dpped in water Focal length of portion of mirror is the air is f, and focal length ofmeror in water is then (Take neltractive index of water5/3)

Discussion

16.	In a particular system, the units of length, mass and time are chosen to be 10cm, 10g and 0.1s respectively. The unit of force in this system will be equivalent to:
Answer» In a particular system, the units of length, mass and time are chosen to be 10cm, 10g and 0.1s respectively. The unit of force in this system will be equivalent to:

Discussion

17.	Question 19Explain why the surface of mortar and pestle (silbatta) used for grinding is etched again after prolonged use?
Answer» Question 19 Explain why the surface of mortar and pestle (silbatta) used for grinding is etched again after prolonged use?

Discussion

18.	The potential difference in an X -ray tube is 5 kV and the current through it is 3.2 mA. Then the number of the electrons striking the target per second is
Answer» The potential difference in an X -ray tube is 5 kV and the current through it is 3.2 mA. Then the number of the electrons striking the target per second is

Discussion

19.	State true or false: If pole star appears to be stationary in respect to earth so it means that it is revolves around the sun.
Answer» State true or false: If pole star appears to be stationary in respect to earth so it means that it is revolves around the sun.

Discussion

20.	Lightning and thunder occur at the same time and at the same distance from us.Yet, lightning is seen earlier than thunder is heard. Can you explain this? [2 MARKS]
Answer» Lightning and thunder occur at the same time and at the same distance from us.Yet, lightning is seen earlier than thunder is heard. Can you explain this? [2 MARKS]

Discussion

21.	46.What is mean by electrical conductivity
Answer» 46.What is mean by electrical conductivity

Discussion

22.	The current in a wire depends on time as i =5 sin(2t). Find the charge crossing through a cross section in time interval t=0 to t=17.27 s is
Answer» The current in a wire depends on time as i =5 sin(2t). Find the charge crossing through a cross section in time interval t=0 to t=17.27 s is

Discussion

23.	64. The sound intensity level at a point 4m from the point source is 10db then the sound level at a distance 2m from the same source will be
Answer» 64. The sound intensity level at a point 4m from the point source is 10db then the sound level at a distance 2m from the same source will be

Discussion

24.	What is a huge group of stars, gas and dust in space called?
Answer» What is a huge group of stars, gas and dust in space called?

Discussion

25.	What is difference between Average speed and Non-uniform speed ?
Answer» What is difference between Average speed and Non-uniform speed ?

Discussion

26.	We learnt that touching is the repulsive force between atoms and that two things are never really in contact. If so then does this repulsive force vary for different things? Are there things with a repulsive force strong enough for us to see that we can't touch it?
Answer» We learnt that touching is the repulsive force between atoms and that two things are never really in contact. If so then does this repulsive force vary for different things? Are there things with a repulsive force strong enough for us to see that we can't touch it?

Discussion

27.	The floating of an object in a fluid depends on
Answer» The floating of an object in a fluid depends on

Discussion

28.	30.A 10 l flask contains 0.2 mile of CH4 and 0.3 mole of of H2 at 25 . Then, the total pressure inside the flask will be
Answer» 30.A 10 l flask contains 0.2 mile of CH4 and 0.3 mole of of H2 at 25 . Then, the total pressure inside the flask will be

Discussion

29.	Speed of a body travelling North changed from 4 m/s to 6 m/s in 1 s. Magnitude of avg acceleration of the body is
Answer» Speed of a body travelling North changed from 4 m/s to 6 m/s in 1 s. Magnitude of avg acceleration of the body is

Discussion

30.	Ajay asked his father that pole star is the only star in the sky that does not move as night passes. Which could be the best reason explaining this?
Answer» Ajay asked his father that pole star is the only star in the sky that does not move as night passes. Which could be the best reason explaining this?

Discussion

31.	31.if a body covers 1/3 part of circle then find displacement
Answer» 31.if a body covers 1/3 part of circle then find displacement

Discussion

32.	If A and B are any two sets, then A – B is equal to ____________.
Answer» If A and B are any two sets, then A – B is equal to ____________.

Discussion

33.	56. The normal density of gold is D and its modulus is B. the increase in density of piece of gold when pressure P is applied uniformly from all sides : 1. DP/2B 2. DB/2P 3. DP/B-P 4. DB/B-P
Answer» 56. The normal density of gold is D and its modulus is B. the increase in density of piece of gold when pressure P is applied uniformly from all sides : 1. DP/2B 2. DB/2P 3. DP/B-P 4. DB/B-P

Discussion

34.	The earth revolves around the sun. Can it be called a satellite of the sun?
Answer» The earth revolves around the sun. Can it be called a satellite of the sun?

Discussion

35.	What are the characteristics of a static electric charge?
Answer» What are the characteristics of a static electric charge?

Discussion

36.	Explain why a real image can be projected on a screen but a virtual image cannot. Also, give one example of each type of image.
Answer» Explain why a real image can be projected on a screen but a virtual image cannot. Also, give one example of each type of image.

Discussion

37.	Question 25An archer shoots an arrow in the air horizontally. However, after moving some distance, the arrow falls to the ground. Name the initial force that sets the arrow in motion. Explain why the arrow ultimately falls down.
Answer» Question 25 An archer shoots an arrow in the air horizontally. However, after moving some distance, the arrow falls to the ground. Name the initial force that sets the arrow in motion. Explain why the arrow ultimately falls down.

Discussion

38.	___ is the range of voltage that must be(or can be) applied to household electrical appliances.
Answer» ___ is the range of voltage that must be(or can be) applied to household electrical appliances.

Discussion

39.	how come if temperature is cons†an t change in internal enegery is cons
Answer» how come if temperature is cons†an t change in internal enegery is cons

Discussion

40.	Two plane mirrors are initially inclined at 30∘ and they move apart with an addition of 30∘ till the angle become 120∘. Find the sum of all the images formed. (Mirrors are inclined symmetrically)
Answer» Two plane mirrors are initially inclined at $30^{\circ}$ and they move apart with an addition of $30^{\circ}$ till the angle become $120^{\circ}$ . Find the sum of all the images formed. (Mirrors are inclined symmetrically)

Discussion

41.	For _______ value of K∈(0,32) does the following system of equation admits a non-trivial solution.x + Ky + 3z = 0;Kx + 2y + 2z = 0;2x + 3y + 4z =0 1.25
Answer» For _______ value of $K \in (0, \frac{3}{2})$ does the following system of equation admits a non-trivial solution. x + Ky + 3z = 0; Kx + 2y + 2z = 0; 2x + 3y + 4z =0 1.25

Discussion

42.	Why is it easier to open a door by applying the force at free end of it?
Answer» Why is it easier to open a door by applying the force at free end of it?

Discussion

43.	Are the following statements true or false? (a) The pressure of air inside an inflated balloon is equal to atmospheric pressure. (b) Fluids always flow from higher pressure to lower pressure. (c) If area is reduced, pressure is reduced. (d) Standing on a cane chair increases the possibility of the cane breaking due to increased pressure.
Answer» Are the following statements true or false? (a) The pressure of air inside an inflated balloon is equal to atmospheric pressure. (b) Fluids always flow from higher pressure to lower pressure. (c) If area is reduced, pressure is reduced. (d) Standing on a cane chair increases the possibility of the cane breaking due to increased pressure.

43.

Are the following statements true or false? (a) The pressure of air inside an inflated balloon is equal to atmospheric pressure. (b) Fluids always flow from higher pressure to lower pressure. (c) If area is reduced, pressure is reduced. (d) Standing on a cane chair increases the possibility of the cane breaking due to increased pressure.

Answer»

Are the following statements true or false?

(a) The pressure of air inside an inflated balloon is equal to atmospheric pressure.

(b) Fluids always flow from higher pressure to lower pressure.

(c) If area is reduced, pressure is reduced.

(d) Standing on a cane chair increases the possibility of the cane breaking due to increased pressure.

Discussion

44.	45.How proton is a fundamental particle?
Answer» 45.How proton is a fundamental particle?

Discussion

45.	What do you mean by conservation of charges?
Answer» What do you mean by conservation of charges?

Discussion

46.	A body of volume V and density ρ is kept completely immersed in a liquid of density ρL. If g is the acceleration due to gravity, write expressions for the following : (i) Weight of the body (ii) The upthrust on the body (iii) Apparent weight of the body in the liquid (iv) The loss in weight of the body
Answer» A body of volume V and density $ρ$ is kept completely immersed in a liquid of density $ρ_{L}$ . If g is the acceleration due to gravity, write expressions for the following : (i) Weight of the body (ii) The upthrust on the body (iii) Apparent weight of the body in the liquid (iv) The loss in weight of the body

Discussion

47.	While inflating a balloon, whole air escapes from it when its mouth is open. This is because
Answer» While inflating a balloon, whole air escapes from it when its mouth is open. This is because

Discussion

48.	l need more detail about frictional force with diagram
Answer» l need more detail about frictional force with diagram

Discussion

49.	(a) What is the drag? Give two examples for a drag force. (b) How can you reduce the drag on something moving through the air?
Answer» (a) What is the drag? Give two examples for a drag force. (b) How can you reduce the drag on something moving through the air?

Discussion

50.	When speed of a bicycle is increasing on ahorizontal road, the force of friction exerted by theground on the wheels is
Answer» When speed of a bicycle is increasing on ahorizontal road, the force of friction exerted by theground on the wheels is

Discussion

Explore topic-wise InterviewSolutions in .

2.When the velocity of a relativistic charged particle increases. It's specific charge

Two concentric conducting thin spherical shells A and B having radii rA and rB(rB&gt;rA) are charged with charges QA and −QB (|QB|&gt;|QA|). The electric field along a line, (passing through the centre) varies with distance x from the centre as

Wet clothes dry more quickly on a warm dry day than on a cold humid day. Explain.

Write a paragraph on the birth and lifecycle of stars using figure 20.1.

Pure water is kept in a container and electricity is passed through it. The level of water in the container ____.

The phase transition in which a liquid turns into a solid is called as _______

Question 10Ultrasound has frequency of vibration(a) Between 20 and 20,000 Hz(b) Below 20 Hz(c) Above 20,000 Hz(d) Between 500 and 10,000 Hz

when one mole of monoatomic gas is mixed with one mole of triatomic gas,then the equivalent value of g for the mixture will be(vibration mode neglected)

A ball of glass bounces higher than a ball of rubber. Why so?

73. Why is the potential difference across any one of the resistors in series is directly proportional to resistance ??(But V is inversely proportional to R)

How many times more intense is 90 dB sound than 40 dB sound?

Question 1In which of these mediums can sound travel?(i) Wood(ii) Water(iii) Air(iv) Vacuum

Mass × change in velocity = ___ × time interval.

A concave mirtor is hait dpped in water Focal length of portion of mirror is the air is f, and focal length ofmeror in water is then (Take neltractive index of water5/3)

In a particular system, the units of length, mass and time are chosen to be 10cm, 10g and 0.1s respectively. The unit of force in this system will be equivalent to:

Question 19Explain why the surface of mortar and pestle (silbatta) used for grinding is etched again after prolonged use?

The potential difference in an X -ray tube is 5 kV and the current through it is 3.2 mA. Then the number of the electrons striking the target per second is

State true or false: If pole star appears to be stationary in respect to earth so it means that it is revolves around the sun.

Lightning and thunder occur at the same time and at the same distance from us.Yet, lightning is seen earlier than thunder is heard. Can you explain this? [2 MARKS]

46.What is mean by electrical conductivity

The current in a wire depends on time as i =5 sin(2t). Find the charge crossing through a cross section in time interval t=0 to t=17.27 s is

64. The sound intensity level at a point 4m from the point source is 10db then the sound level at a distance 2m from the same source will be

What is a huge group of stars, gas and dust in space called?

What is difference between Average speed and Non-uniform speed ?

We learnt that touching is the repulsive force between atoms and that two things are never really in contact. If so then does this repulsive force vary for different things? Are there things with a repulsive force strong enough for us to see that we can't touch it?

The floating of an object in a fluid depends on

30.A 10 l flask contains 0.2 mile of CH4 and 0.3 mole of of H2 at 25 . Then, the total pressure inside the flask will be

Speed of a body travelling North changed from 4 m/s to 6 m/s in 1 s. Magnitude of avg acceleration of the body is

Ajay asked his father that pole star is the only star in the sky that does not move as night passes. Which could be the best reason explaining this?

31.if a body covers 1/3 part of circle then find displacement

If A and B are any two sets, then A – B is equal to ____________.

56. The normal density of gold is D and its modulus is B. the increase in density of piece of gold when pressure P is applied uniformly from all sides : 1. DP/2B 2. DB/2P 3. DP/B-P 4. DB/B-P

The earth revolves around the sun. Can it be called a satellite of the sun?

What are the characteristics of a static electric charge?

Explain why a real image can be projected on a screen but a virtual image cannot. Also, give one example of each type of image.

Question 25An archer shoots an arrow in the air horizontally. However, after moving some distance, the arrow falls to the ground. Name the initial force that sets the arrow in motion. Explain why the arrow ultimately falls down.

___ is the range of voltage that must be(or can be) applied to household electrical appliances.

how come if temperature is cons†an t change in internal enegery is cons

Two plane mirrors are initially inclined at 30∘ and they move apart with an addition of 30∘ till the angle become 120∘. Find the sum of all the images formed. (Mirrors are inclined symmetrically)

For _______ value of K∈(0,32) does the following system of equation admits a non-trivial solution.x + Ky + 3z = 0;Kx + 2y + 2z = 0;2x + 3y + 4z =0 1.25

Why is it easier to open a door by applying the force at free end of it?

45.How proton is a fundamental particle?

What do you mean by conservation of charges?

While inflating a balloon, whole air escapes from it when its mouth is open. This is because

l need more detail about frictional force with diagram

(a) What is the drag? Give two examples for a drag force. (b) How can you reduce the drag on something moving through the air?

When speed of a bicycle is increasing on ahorizontal road, the force of friction exerted by theground on the wheels is

Two concentric conducting thin spherical shells A and B having radii rA and rB(rB>rA) are charged with charges QA and −QB (|QB|>|QA|). The electric field along a line, (passing through the centre) varies with distance x from the centre as