16569 + Interview Questions in Physics

1.	can we use right hand thumb rule for electric motors? because in my text book inorder to check the direction of magnetic force in electric motor they used right hand rule and never mentioned about left hand rule , they simply asked us to reverse the direction for negative charge?
Answer» can we use right hand thumb rule for electric motors? because in my text book inorder to check the direction of magnetic force in electric motor they used right hand rule and never mentioned about left hand rule , they simply asked us to reverse the direction for negative charge?

Discussion

2.	If Avogadro's number is 6×1023, then the number of protons, neutrons and electrons in 14 g of 6C14 are respectively:
Answer» If Avogadro's number is $6 \times 10^{23}$ , then the number of protons, neutrons and electrons in 14 g of $_{6} C^{14}$ are respectively:

Discussion

3.	What constitute electricity?
Answer» What constitute electricity?

Discussion

4.	What will happen to the wavelength of light when it goes from optically rarer to denser medium
Answer» What will happen to the wavelength of light when it goes from optically rarer to denser medium

Discussion

5.	Question 113(i) Sunscreens block harmful ultraviolet (UV) rays produced by the sun. Each sunscreen has a Sun Protection Factor (SPF) that tells you how many minutes you can stay in the sun before you receive one minute of burning UV rays. e.g. If you apply sunscreen with SPF 15, you get one minute of UV rays for every 15 minutes you stay in the sun. - A sunscreen with SPF 15 allows only 115 of the sun's UV rays. What percent of UV rays does the sunscreen with SPF 15 abort?
Answer» Question 113(i) Sunscreens block harmful ultraviolet (UV) rays produced by the sun. Each sunscreen has a Sun Protection Factor (SPF) that tells you how many minutes you can stay in the sun before you receive one minute of burning UV rays. e.g. If you apply sunscreen with SPF 15, you get one minute of UV rays for every 15 minutes you stay in the sun. - A sunscreen with SPF 15 allows only $\frac{1}{15}$ of the sun's UV rays. What percent of UV rays does the sunscreen with SPF 15 abort?

5.

Question 113(i) Sunscreens block harmful ultraviolet (UV) rays produced by the sun. Each sunscreen has a Sun Protection Factor (SPF) that tells you how many minutes you can stay in the sun before you receive one minute of burning UV rays. e.g. If you apply sunscreen with SPF 15, you get one minute of UV rays for every 15 minutes you stay in the sun. - A sunscreen with SPF 15 allows only 115 of the sun's UV rays. What percent of UV rays does the sunscreen with SPF 15 abort?

Answer»

Question 113(i)

Sunscreens block harmful ultraviolet (UV) rays produced by the sun. Each sunscreen has a Sun Protection Factor (SPF) that tells you how many minutes you can stay in the sun before you receive one minute of burning UV rays. e.g. If you apply sunscreen with SPF 15, you get one minute of UV rays for every 15 minutes you stay in the sun.
- A sunscreen with SPF 15 allows only $\frac{1}{15}$ of the sun's UV rays. What percent of UV rays does the sunscreen with SPF 15 abort?

Discussion

6.	A postage stamp kept below a rectangular glass block of refractive index 1.5 when viewed from vertically above, it appears to be raised by 7.0 mm. Calculate the thickness of the glass slab.
Answer» A postage stamp kept below a rectangular glass block of refractive index 1.5 when viewed from vertically above, it appears to be raised by 7.0 mm. Calculate the thickness of the glass slab.

Discussion

7.	The weight of an astronaut and his space suit on Earth is 60 kgf and 30 kgf respectively. Their combined weight on Moon will be___ kgf. (Acceleration due to gravity on Moon is 16 of acceleration due to gravity on Earth)
Answer» The weight of an astronaut and his space suit on Earth is 60 kgf and 30 kgf respectively. Their combined weight on Moon will be___ kgf. (Acceleration due to gravity on Moon is $\frac{1}{6}$ of acceleration due to gravity on Earth)

Discussion

8.	Which of the following is not a natural resource? (a) snake (b) wind (c) wooden house (d) mango tree
Answer» Which of the following is not a natural resource? (a) snake (b) wind (c) wooden house (d) mango tree

Discussion

9.	Is image formed by a plane mirror real image or virtual image ?
Answer» Is image formed by a plane mirror real image or virtual image ?

Discussion

10.	Escape velocity of a body on a planet is 100ms−1. What is the gravitational potential energy of the body at the surface, if the mass of the body is 1 kg?
Answer» Escape velocity of a body on a planet is $100 m s^{- 1}$ . What is the gravitational potential energy of the body at the surface, if the mass of the body is $1 k g$ ?

Discussion

11.	How does Fermats principle of least time prove that light always retraces its path?
Answer» How does Fermats principle of least time prove that light always retraces its path?

Discussion

12.	In Fleming's hand rules, can we change the finger representing current with other? Meaning that can we interchange the representation given by fingers
Answer» In Fleming's hand rules, can we change the finger representing current with other? Meaning that can we interchange the representation given by fingers

Discussion

13.	Name the major programme started to replenish forests.
Answer» Name the major programme started to replenish forests.

Discussion

14.	An electromagnetic wave has a frequency of 500 MHz and a wavelength of 60 cm. (a) Calculate the speed of the wave. (b) Name the medium through which it is travelling.
Answer» An electromagnetic wave has a frequency of 500 MHz and a wavelength of 60 cm. (a) Calculate the speed of the wave. (b) Name the medium through which it is travelling.

14.

An electromagnetic wave has a frequency of 500 MHz and a wavelength of 60 cm. (a) Calculate the speed of the wave. (b) Name the medium through which it is travelling.

Answer»

An electromagnetic wave has a frequency of 500 MHz and a wavelength of 60 cm.

(a) Calculate the speed of the wave.

(b) Name the medium through which it is travelling.

Discussion

15.	A straight wire carrying electric current is moving out of plane of paper and is perpendicular to it and the current is also upwards. What is the direction and type of induced magnetic field lines? [1 MARK]
Answer» A straight wire carrying electric current is moving out of plane of paper and is perpendicular to it and the current is also upwards. What is the direction and type of induced magnetic field lines? [1 MARK]

Discussion

16.	Answer the following: a. Give two examples of use of fluid pressure by us. b. If a pentagonal cylinder filled with water is connected with another cylinder of different volume, in which cylinder would the level of water be greater finally? Both cylinders are open at the top. [5 MARKS]
Answer» Answer the following: a. Give two examples of use of fluid pressure by us. b. If a pentagonal cylinder filled with water is connected with another cylinder of different volume, in which cylinder would the level of water be greater finally? Both cylinders are open at the top. [5 MARKS]

16.

Answer the following: a. Give two examples of use of fluid pressure by us. b. If a pentagonal cylinder filled with water is connected with another cylinder of different volume, in which cylinder would the level of water be greater finally? Both cylinders are open at the top. [5 MARKS]

Answer»

Answer the following:

a. Give two examples of use of fluid pressure by us.

b.

If a pentagonal cylinder filled with water is connected with another cylinder of different volume, in which cylinder would the level of water be greater finally? Both cylinders are open at the top. [5 MARKS]

Discussion

17.	What do you understand by the term couple? State its effect. Give two examples in our daily life where couple is applied to turn a body.
Answer» What do you understand by the term couple? State its effect. Give two examples in our daily life where couple is applied to turn a body.

Discussion

18.	On reversing the direction of current in a wire, the magnetic field produced by it: (a) gets reversed in direction (b) increases in strength (c) decreases in strength (d) remains unchanged in strength and direction.
Answer» On reversing the direction of current in a wire, the magnetic field produced by it: (a) gets reversed in direction (b) increases in strength (c) decreases in strength (d) remains unchanged in strength and direction.

Discussion

19.	A cook uses a fire tong of length 25 cm to lift a piece of coal of mass 250g. If he applies his effort at distance of 15cm from the coal, what is the effort required in SI units.
Answer» A cook uses a fire tong of length 25 cm to lift a piece of coal of mass 250g. If he applies his effort at distance of 15cm from the coal, what is the effort required in SI units.

Discussion

20.	Tina has a LED of resistance 10 Ω which will only light up if the current provided is 1A. Below 1A current it won't light up, above that the LED will burst. She also has 10 two volt cells. Find out how many cells will Ram need to light up the LED?
Answer» Tina has a LED of resistance 10 Ω which will only light up if the current provided is 1A. Below 1A current it won't light up, above that the LED will burst. She also has 10 two volt cells. Find out how many cells will Ram need to light up the LED?

Discussion

21.	A source of sound and a listener are moving in the same direction, not parallel to each other, with unequal velocities vS and vL respectively. If the velocity of sound in the medium is v and its true frequency is f, the frequency perceived by the listener (f *) is given by:
Answer» A source of sound and a listener are moving in the same direction, not parallel to each other, with unequal velocities $v_{S}$ and $v_{L}$ respectively. If the velocity of sound in the medium is $v$ and its true frequency is $f$ , the frequency perceived by the listener ( $f *$ ) is given by:

Discussion

22.	A student very cautiously traces the path of a ray through a glass slab for different values of the angle of incidence (∠i). He then measures the corresponding values of the angle of refraction (∠r) and the angle of emergence (∠e) for every value of the angle of incidence. On analysing these measurements of angles, his conclusion would be : (a) ∠i>∠r>∠e (b) ∠i=∠e>∠r (c) ∠i<∠r<∠e (d) ∠i=∠e<∠r
Answer» A student very cautiously traces the path of a ray through a glass slab for different values of the angle of incidence $(∠ i)$ . He then measures the corresponding values of the angle of refraction $(∠ r)$ and the angle of emergence $(∠ e)$ for every value of the angle of incidence. On analysing these measurements of angles, his conclusion would be : (a) $∠ i > ∠ r > ∠ e$ (b) $∠ i = ∠ e > ∠ r$ (c) $∠ i < ∠ r < ∠ e$ (d) $∠ i = ∠ e < ∠ r$

Discussion

23.	Why can gamma rays travel through the air for a long distance?
Answer» Why can gamma rays travel through the air for a long distance?

Discussion

24.	A nucleus AZX going through a β+ decay will end up taking what configuration?
Answer» A nucleus $_{Z}^{A} X$ going through a $β^{+}$ decay will end up taking what configuration?

Discussion

25.	A charge +q is fixed at each of the points x=x0, x=3x0, x=5x0…… infinity, on the x - axis and a charge -q is fixed at each of the points x=2x0, x=4x0, x=6x0…… infinity. Here x0 is a positive constant. The potential at the origin due to the above system of charges is
Answer» A charge +q is fixed at each of the points $x = x_{0}, x = 3 x_{0}, x = 5 x_{0} \dots \dots$ infinity, on the x - axis and a charge -q is fixed at each of the points $x = 2 x_{0}, x = 4 x_{0}, x = 6 x_{0} \dots \dots$ infinity. Here $x_{0}$ is a positive constant. The potential at the origin due to the above system of charges is

Discussion

26.	Potential difference applied to an X-ray tube is 5 kV and the current through it is 3.2 mA. The number of the electrons striking the target per second is
Answer» Potential difference applied to an X-ray tube is $5 k V$ and the current through it is $3.2 m A$ . The number of the electrons striking the target per second is

Discussion

27.	Apart from the availability of forest products, name two other things which are affected by the destruction of forests.
Answer» Apart from the availability of forest products, name two other things which are affected by the destruction of forests.

Discussion

28.	The ways by which the magnetic field of the solenoid can be made stronger are:
Answer» The ways by which the magnetic field of the solenoid can be made stronger are:

Discussion

29.	Calculate the resistance between the points X and Y in the network shown below. [4 MARKS]
Answer» Calculate the resistance between the points X and Y in the network shown below. [4 MARKS]

Discussion

30.	An electric generator converts : (a) electrical energy into mechanical energy (b) mechanical energy into hear eneregy (c) electrical energy into chemical energy (d) mechanical energy into electrical energy
Answer» An electric generator converts : (a) electrical energy into mechanical energy (b) mechanical energy into hear eneregy (c) electrical energy into chemical energy (d) mechanical energy into electrical energy

30.

An electric generator converts : (a) electrical energy into mechanical energy (b) mechanical energy into hear eneregy (c) electrical energy into chemical energy (d) mechanical energy into electrical energy

Answer»

An electric generator converts :

(a) electrical energy into mechanical energy

(b) mechanical energy into hear eneregy

(c) electrical energy into chemical energy

(d) mechanical energy into electrical energy

Discussion

31.	What is the shape of the graph between V and I, where V is the potential difference applied between the ends of a wire and I is the current flowing through it ?
Answer» What is the shape of the graph between V and I, where V is the potential difference applied between the ends of a wire and I is the current flowing through it ?

Discussion

32.	A body weighs 60N on Earth. What will be its weight on the moon if the acceleration due to gravity on Moon's surface is g6? Takeg=10ms−2
Answer» A body weighs $60 N$ on Earth. What will be its weight on the moon if the acceleration due to gravity on Moon's surface is $\frac{g}{6}$ ? $Take g = 10 m s^{- 2}$

Discussion

33.	Focal length of convex lens is 20 cm, focal length of concave mirror is 30 cm. And the separation between lens and mirror is 90 cm. If the object is placed 60 cm before lens, find out position of image formed by concave mirror?
Answer» Focal length of convex lens is 20 cm, focal length of concave mirror is 30 cm. And the separation between lens and mirror is 90 cm. If the object is placed 60 cm before lens, find out position of image formed by concave mirror?

33.

Focal length of convex lens is 20 cm, focal length of concave mirror is 30 cm. And the separation between lens and mirror is 90 cm. If the object is placed 60 cm before lens, find out position of image formed by concave mirror?

Answer»

Focal length of convex lens is 20 cm, focal length of concave mirror is 30 cm. And the separation between lens and mirror is 90 cm. If the object is placed 60 cm before lens, find out position of image formed by concave mirror?

Discussion

34.	Out of a radioactive sample 90% is found after one day. What percent of the original sample can be found after 2 days ?
Answer» Out of a radioactive sample 90% is found after one day. What percent of the original sample can be found after 2 days ?

Discussion

35.	Convergence of concave mirror can be decreased by dipping in
Answer» Convergence of concave mirror can be decreased by dipping in

Discussion

36.	The fuel used in a nuclear reactor is ______.
Answer» The fuel used in a nuclear reactor is ______.

Discussion

37.	Please explain the working of thermocouple
Answer» Please explain the working of thermocouple

Discussion

38.	Which of the following plays a direct role in the formation of rain droplets?
Answer» Which of the following plays a direct role in the formation of rain droplets?

Discussion

39.	The turn ratio of a transformer is given as 2:3. If the current through the primary coil is 3 A, then calculate the current through load resistance.
Answer» The turn ratio of a transformer is given as $2 : 3$ . If the current through the primary coil is $3 A$ , then calculate the current through load resistance.

Discussion

40.	In a circular motion of a stone tied to a string, ___
Answer» In a circular motion of a stone tied to a string, ___

Discussion

41.	Explain refractive index with example using sin I by sin r??
Answer» Explain refractive index with example using sin I by sin r??

Discussion

42.	under what conditions is the force acting on a current carrying conductor in a uniform magnetic field minimum ??
Answer» under what conditions is the force acting on a current carrying conductor in a uniform magnetic field minimum ??

Discussion

43.	Explain e=mc^2
Answer» Explain e=mc^2

Discussion

44.	What are the disadvantages of using solar panels ?
Answer» What are the disadvantages of using solar panels ?

Discussion

45.	The relative refractive index can be:
Answer» The relative refractive index can be:

Discussion

46.	The current-voltage graph for a given metallic wire at two different temperatures T1 and T2 is shown in the figure. The temperature T1 and T2 are related as:
Answer» The current-voltage graph for a given metallic wire at two different temperatures $T_{1}$ and $T_{2}$ is shown in the figure. The temperature $T_{1}$ and $T_{2}$ are related as:

Discussion

47.	The far point of a myopic person is 80 cm in front of the eye. What is the power of the lens required to enable him to see the distant objects clearly?
Answer» The far point of a myopic person is 80 cm in front of the eye. What is the power of the lens required to enable him to see the distant objects clearly?

Discussion

48.	Which river in our country has a sustainable conservation plan? __
Answer» Which river in our country has a sustainable conservation plan? __

Discussion

49.	In the circuit shown below, calculate the value of x if the equivalent resistance between the points A and B is 4Ω.
Answer» In the circuit shown below, calculate the value of x if the equivalent resistance between the points A and B is $4 Ω$ .

Discussion

50.	Question 3 Under which of the conditions a concave mirror can form a real image larger than the actual object? (a) When the object is kept at a distance equal to its radius of curvature. (b) When object is kept at a distance less than its focal length. (c) When object is placed between the focus and centre of curvature. (d) When object is kept at a distance greater than its radius of curvature.
Answer» Question 3 Under which of the conditions a concave mirror can form a real image larger than the actual object? (a) When the object is kept at a distance equal to its radius of curvature. (b) When object is kept at a distance less than its focal length. (c) When object is placed between the focus and centre of curvature. (d) When object is kept at a distance greater than its radius of curvature.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

can we use right hand thumb rule for electric motors? because in my text book inorder to check the direction of magnetic force in electric motor they used right hand rule and never mentioned about left hand rule , they simply asked us to reverse the direction for negative charge?

If Avogadro's number is 6×1023, then the number of protons, neutrons and electrons in 14 g of 6C14 are respectively:

What constitute electricity?

What will happen to the wavelength of light when it goes from optically rarer to denser medium

A postage stamp kept below a rectangular glass block of refractive index 1.5 when viewed from vertically above, it appears to be raised by 7.0 mm. Calculate the thickness of the glass slab.

The weight of an astronaut and his space suit on Earth is 60 kgf and 30 kgf respectively. Their combined weight on Moon will be___ kgf. (Acceleration due to gravity on Moon is 16 of acceleration due to gravity on Earth)

Which of the following is not a natural resource? (a) snake (b) wind (c) wooden house (d) mango tree

Is image formed by a plane mirror real image or virtual image ?

Escape velocity of a body on a planet is 100ms−1. What is the gravitational potential energy of the body at the surface, if the mass of the body is 1 kg?

How does Fermats principle of least time prove that light always retraces its path?

In Fleming's hand rules, can we change the finger representing current with other? Meaning that can we interchange the representation given by fingers

Name the major programme started to replenish forests.

An electromagnetic wave has a frequency of 500 MHz and a wavelength of 60 cm. (a) Calculate the speed of the wave. (b) Name the medium through which it is travelling.

A straight wire carrying electric current is moving out of plane of paper and is perpendicular to it and the current is also upwards. What is the direction and type of induced magnetic field lines? [1 MARK]

Answer the following: a. Give two examples of use of fluid pressure by us. b. If a pentagonal cylinder filled with water is connected with another cylinder of different volume, in which cylinder would the level of water be greater finally? Both cylinders are open at the top. [5 MARKS]

What do you understand by the term couple? State its effect. Give two examples in our daily life where couple is applied to turn a body.

On reversing the direction of current in a wire, the magnetic field produced by it: (a) gets reversed in direction (b) increases in strength (c) decreases in strength (d) remains unchanged in strength and direction.

A cook uses a fire tong of length 25 cm to lift a piece of coal of mass 250g. If he applies his effort at distance of 15cm from the coal, what is the effort required in SI units.

Tina has a LED of resistance 10 Ω which will only light up if the current provided is 1A. Below 1A current it won't light up, above that the LED will burst. She also has 10 two volt cells. Find out how many cells will Ram need to light up the LED?

A source of sound and a listener are moving in the same direction, not parallel to each other, with unequal velocities vS and vL respectively. If the velocity of sound in the medium is v and its true frequency is f, the frequency perceived by the listener (f *) is given by:

Why can gamma rays travel through the air for a long distance?

A nucleus AZX going through a β+ decay will end up taking what configuration?

A charge +q is fixed at each of the points x=x0, x=3x0, x=5x0…… infinity, on the x - axis and a charge -q is fixed at each of the points x=2x0, x=4x0, x=6x0…… infinity. Here x0 is a positive constant. The potential at the origin due to the above system of charges is

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

Apart from the availability of forest products, name two other things which are affected by the destruction of forests.

The ways by which the magnetic field of the solenoid can be made stronger are:

Calculate the resistance between the points X and Y in the network shown below. [4 MARKS]

An electric generator converts : (a) electrical energy into mechanical energy (b) mechanical energy into hear eneregy (c) electrical energy into chemical energy (d) mechanical energy into electrical energy

What is the shape of the graph between V and I, where V is the potential difference applied between the ends of a wire and I is the current flowing through it ?

A body weighs 60N on Earth. What will be its weight on the moon if the acceleration due to gravity on Moon's surface is g6? Takeg=10ms−2

Focal length of convex lens is 20 cm, focal length of concave mirror is 30 cm. And the separation between lens and mirror is 90 cm. If the object is placed 60 cm before lens, find out position of image formed by concave mirror?

Out of a radioactive sample 90% is found after one day. What percent of the original sample can be found after 2 days ?

Convergence of concave mirror can be decreased by dipping in

The fuel used in a nuclear reactor is ______.

Please explain the working of thermocouple

Which of the following plays a direct role in the formation of rain droplets?

The turn ratio of a transformer is given as 2:3. If the current through the primary coil is 3 A, then calculate the current through load resistance.

In a circular motion of a stone tied to a string, ___

Explain refractive index with example using sin I by sin r??

under what conditions is the force acting on a current carrying conductor in a uniform magnetic field minimum ??

Explain e=mc^2

What are the disadvantages of using solar panels ?

The relative refractive index can be:

The current-voltage graph for a given metallic wire at two different temperatures T1 and T2 is shown in the figure. The temperature T1 and T2 are related as:

The far point of a myopic person is 80 cm in front of the eye. What is the power of the lens required to enable him to see the distant objects clearly?

Which river in our country has a sustainable conservation plan? __

In the circuit shown below, calculate the value of x if the equivalent resistance between the points A and B is 4Ω.