16569 + Interview Questions in Physics

1.	A cell has an emf 1.5 V. When connected across an external resistance of 2Ω, the terminal potential difference forces to 1V. The internal resistance of the cell is
Answer» A cell has an emf 1.5 V. When connected across an external resistance of $2 Ω$ , the terminal potential difference forces to 1V. The internal resistance of the cell is

Discussion

2.	Derive of mirror formula and lenses formula.
Answer» Derive of mirror formula and lenses formula.

Discussion

3.	Discuss the Chipko Movement along with the conditions under which it started and its implications.
Answer» Discuss the Chipko Movement along with the conditions under which it started and its implications.

Discussion

4.	In which of the following cases, the flow of electric current is maximum?
Answer» In which of the following cases, the flow of electric current is maximum?

Discussion

5.	I want a daily examples of image formed under the object by the concept of concave and convex mirror
Answer» I want a daily examples of image formed under the object by the concept of concave and convex mirror

Discussion

6.	Who and how was the gravitational constant G measured?
Answer» Who and how was the gravitational constant G measured?

Discussion

7.	A small ball 'A' of mass 'm' is attached rigidly to the end of a light rod of length 'd'. The structure rotates about an axis perpendicular to the rod and passing through its other end with an angular velocity 'ω'. Calculate the angular momentum of the system about this axis?
Answer» A small ball 'A' of mass 'm' is attached rigidly to the end of a light rod of length 'd'. The structure rotates about an axis perpendicular to the rod and passing through its other end with an angular velocity ' $ω$ '. Calculate the angular momentum of the system about this axis?

Discussion

8.	Question 131(iii) This table shows the mass of one atom for five chemical elements. Use it to answer the questions given. ElementsMass of atom(kg)Titanium7.95×10−26Lead3.44×10−25Silver1.79×10−25Lithium1.15×10−26Hydrogen1.674×10−27 List all the five elements in order from lightest to heaviest.
Answer» Question 131(iii) This table shows the mass of one atom for five chemical elements. Use it to answer the questions given. $\begin{matrix} E l e m e n t s & M a s s o f a t o m (k g) T i t a n i u m & 7.95 \times 10^{- 26} L e a d & 3.44 \times 10^{- 25} S i l v e r & 1.79 \times 10^{- 25} L i t h i u m & 1.15 \times 10^{- 26} H y d r o g e n & 1.674 \times 10^{- 27} \end{matrix}$ List all the five elements in order from lightest to heaviest.

8.

Question 131(iii) This table shows the mass of one atom for five chemical elements. Use it to answer the questions given. ElementsMass of atom(kg)Titanium7.95×10−26Lead3.44×10−25Silver1.79×10−25Lithium1.15×10−26Hydrogen1.674×10−27 List all the five elements in order from lightest to heaviest.

Answer»

Question 131(iii)

This table shows the mass of one atom for five chemical elements.
Use it to answer the questions given.
$\begin{matrix} E l e m e n t s & M a s s o f a t o m (k g) T i t a n i u m & 7.95 \times 10^{- 26} L e a d & 3.44 \times 10^{- 25} S i l v e r & 1.79 \times 10^{- 25} L i t h i u m & 1.15 \times 10^{- 26} H y d r o g e n & 1.674 \times 10^{- 27} \end{matrix}$
List all the five elements in order from lightest to heaviest.

Discussion

9.	A current carrying conductor placed in magnetic field experiences a force. The amount of force experienced by a current carrying conductor in a magnetic field can be increased by:
Answer» A current carrying conductor placed in magnetic field experiences a force. The amount of force experienced by a current carrying conductor in a magnetic field can be increased by:

Discussion

10.	Which defect of vision can be rectified : (a) by using a concave lens ? (b) by using a convex lens ?
Answer» Which defect of vision can be rectified : (a) by using a concave lens ? (b) by using a convex lens ?

Discussion

11.	I received my favourite cologne, bottled in a metallic flask with a spherical cavity, on my birthday in December. I used it modestly only on special occasions, and found that I have finally emptied the bottle in mid-April, when the temperature had risen by 25∘C from December. If the metal's coefficient of superficial (area) expansion is 46 × 10−5/∘C, how much extra cologne can I refill my bottle with, compared to the initial volume (answer in mL)?
Answer» I received my favourite cologne, bottled in a metallic flask with a spherical cavity, on my birthday in December. I used it modestly only on special occasions, and found that I have finally emptied the bottle in mid-April, when the temperature had risen by $25^{\circ} C$ from December. If the metal's coefficient of superficial (area) expansion is $46 \times 10^{- 5} /^{\circ} C$ , how much extra cologne can I refill my bottle with, compared to the initial volume (answer in mL)?

11.

I received my favourite cologne, bottled in a metallic flask with a spherical cavity, on my birthday in December. I used it modestly only on special occasions, and found that I have finally emptied the bottle in mid-April, when the temperature had risen by 25∘C from December. If the metal's coefficient of superficial (area) expansion is 46 × 10−5/∘C, how much extra cologne can I refill my bottle with, compared to the initial volume (answer in mL)?

Answer»

I received my favourite cologne, bottled in a metallic flask with a spherical cavity, on my birthday in December. I used it modestly only on special occasions, and found that I have finally emptied the bottle in mid-April, when the temperature had risen by $25^{\circ} C$ from December. If the metal's coefficient of superficial (area) expansion is $46 \times 10^{- 5} /^{\circ} C$ , how much extra cologne can I refill my bottle with, compared to the initial volume (answer in mL)?

Discussion

12.	Which of the following is not a fossil source of energy? (a) kerosene oil (b) cow-dung cakes (c) CNG (d) coal
Answer» Which of the following is not a fossil source of energy? (a) kerosene oil (b) cow-dung cakes (c) CNG (d) coal

Discussion

13.	What is the capacitance of a cylindrical capacitor?
Answer» What is the capacitance of a cylindrical capacitor?

Discussion

14.	A freezer freezes 1.5 litres of water at 30 ∘C to ice at −15∘C in 1.5 hr. What is the average approximate power of the freezer in watt? Take the specific heat capacity of water to be 4200 J kg−1 ∘C−1 and that of the ice to be 2100 J kg−1 ∘C−1. The specific latent heat of ice is 336000 J kg−1.
Answer» A freezer freezes $1.5$ litres of water at $30^{\circ} C$ to ice at $- 15^{\circ} C$ in $1.5 hr$ . What is the average approximate power of the freezer in watt? Take the specific heat capacity of water to be $4200 {J kg}^{- 1}^{\circ} C^{- 1}$ and that of the ice to be $2100 {J kg}^{- 1}^{\circ} C^{- 1}$ . The specific latent heat of ice is $336000 {J kg}^{- 1}$ .

Discussion

15.	A cannon of mass 1000 kg can fire a bolt of 20 kg with a muzzle velocity (the relative velocity between the cannon and the bolt) of 300 m/s. If the cannon is free to move, the backward velocity of cannon after the bolt is fired will be
Answer» A cannon of mass 1000 kg can fire a bolt of 20 kg with a muzzle velocity (the relative velocity between the cannon and the bolt) of 300 m/s. If the cannon is free to move, the backward velocity of cannon after the bolt is fired will be

Discussion

16.	Machenicnism of light?
Answer» Machenicnism of light?

Discussion

17.	Water in a pond appears to be only three - quarter of its actual depth. What property of light is responsible for this observation?
Answer» Water in a pond appears to be only three - quarter of its actual depth. What property of light is responsible for this observation?

Discussion

18.	A meteorite approaching a planet of mass M (in the straight line passing through the centre of the planet) collides with an automatic space station orbiting the planet in a circular trajectory of radius R. The mass of the station is ten times as large as the mass of the meteorite. As a result of the collision, the meteorite sticks in the station which goes over to a new orbit the minimum distance R/2 from the planet. Speed of the meteorite just before it collides with the planet is:
Answer» A meteorite approaching a planet of mass $M$ (in the straight line passing through the centre of the planet) collides with an automatic space station orbiting the planet in a circular trajectory of radius $R$ . The mass of the station is ten times as large as the mass of the meteorite. As a result of the collision, the meteorite sticks in the station which goes over to a new orbit the minimum distance $R / 2$ from the planet. Speed of the meteorite just before it collides with the planet is:

Discussion

19.	List 4 characterestcha of image formed by concave mirror
Answer» List 4 characterestcha of image formed by concave mirror

Discussion

20.	A current of 0.43 A is flowing through a wire of thickness 2 cm. If there are 1018 electrons per cm3 of the wire, calculate the drift velocity of electrons in ms−1. Take the electron charge as 1.6×10−19 C.
Answer» A current of $0.43 A$ is flowing through a wire of thickness $2 c m$ . If there are $10^{18}$ electrons per $c m^{3}$ of the wire, calculate the drift velocity of electrons in $m s^{- 1}$ . Take the electron charge as $1.6 \times 10^{- 19} C$ .

Discussion

21.	Calculate the refractive index of the medium Y, when a light ray enters from air at an angle ∠i=45∘, and ∠r=30∘? 0.7
Answer» Calculate the refractive index of the medium Y, when a light ray enters from air at an angle $∠ i = 45^{\circ}$ , and $∠ r = 30^{\circ}$ ? 0.7

21.

Calculate the refractive index of the medium Y, when a light ray enters from air at an angle ∠i=45∘, and ∠r=30∘? 0.7

Answer» Calculate the refractive index of the medium Y, when a light ray enters from air at an angle

∠ i = 45^{\circ}

, and

∠ r = 30^{\circ}

?

0.7

Discussion

22.	If two mirrors are kept at 60∘ to each other, then the number of images formed by them is____.
Answer» If two mirrors are kept at $60^{\circ}$ to each other, then the number of images formed by them is____.

Discussion

23.	Why is a normal eye not able to see clearly the objects placed closer than 25cm? [3 MARKS]
Answer» Why is a normal eye not able to see clearly the objects placed closer than 25cm? [3 MARKS]

Discussion

24.	Why is electric potential zero at infinity?
Answer» Why is electric potential zero at infinity?

Discussion

25.	A man's speed with the current is 15 km/hr and the speed of the current is 2.5 km/hr. The man's speed against the current is
Answer» A man's speed with the current is 15 km/hr and the speed of the current is 2.5 km/hr. The man's speed against the current is

Discussion

26.	Find out the image position formed by concave mirror, considering the image formed by plane mirror as an object for concave mirror.
Answer» Find out the image position formed by concave mirror, considering the image formed by plane mirror as an object for concave mirror.

26.

Find out the image position formed by concave mirror, considering the image formed by plane mirror as an object for concave mirror.

Answer»

Find out the image position formed by concave mirror, considering the image formed by plane mirror as an object for concave mirror.

Discussion

27.	3.(C) How does the velocity of light vary with change in the optical density of the media?
Answer» 3.(C) How does the velocity of light vary with change in the optical density of the media?

Discussion

28.	When a body is deformed, its centre of gravity
Answer» When a body is deformed, its centre of gravity

Discussion

29.	The net resistance of an ammeter should be small to ensure that:
Answer» The net resistance of an ammeter should be small to ensure that:

Discussion

30.	Generally, women have a shriller voice than men, this is because they produce a sound which has higher:
Answer» Generally, women have a shriller voice than men, this is because they produce a sound which has higher:

Discussion

31.	When an object is placed 20 cm from a concave mirror, a real image magnified three times is formed. Find : (a) the focal length of the mirror. (b) Where must the object be placed to give a virtual image three times the height of the object ?
Answer» When an object is placed 20 cm from a concave mirror, a real image magnified three times is formed. Find : (a) the focal length of the mirror. (b) Where must the object be placed to give a virtual image three times the height of the object ?

Discussion

32.	Two resistances R1 and R2 are joined with two batteries of emf E1 and E2. If E2 is short circuited, the current through R1 is
Answer» Two resistances R₁ and R₂ are joined with two batteries of emf E₁and E₂. If E₂ is short circuited, the current through R₁is

32.

Two resistances R1 and R2 are joined with two batteries of emf E1 and E2. If E2 is short circuited, the current through R1 is

Answer»

Two resistances R₁ and R₂ are joined with two batteries of emf E₁and E₂. If E₂ is short circuited, the current through R₁is

Discussion

33.	State and explain the New Cartesian Sign Convention for spherical lenses.
Answer» State and explain the New Cartesian Sign Convention for spherical lenses.

Discussion

34.	The angle of reflection is equal to the angle of incidence : (a) always (b) sometimes (c) under special conditions (d) never
Answer» The angle of reflection is equal to the angle of incidence : (a) always (b) sometimes (c) under special conditions (d) never

Discussion

35.	How is coal gas obtained? Enlist its uses.
Answer» How is coal gas obtained? Enlist its uses.

Discussion

36.	What should be the minimum wind speed for the satisfactory working of a wind-powered electric generator?
Answer» What should be the minimum wind speed for the satisfactory working of a wind-powered electric generator?

Discussion

37.	OA is an object with height 4 cm and O'A' is the image of the object. Find the image height and nature of the image formed.
Answer» OA is an object with height $4 c m$ and O'A' is the image of the object. Find the image height and nature of the image formed.

Discussion

38.	State and explain the Clock face rule for determining the polarities of a circular wire carrying current.
Answer» State and explain the Clock face rule for determining the polarities of a circular wire carrying current.

Discussion

39.	What is a spehirical mirror ?
Answer» What is a spehirical mirror ?

Discussion

40.	An electric charge in uniform motion produces :
Answer» An electric charge in uniform motion produces :

Discussion

41.	An electron in an atom:
Answer» An electron in an atom:

Discussion

42.	How can we define electric potential in a simple way?
Answer» How can we define electric potential in a simple way?

Discussion

43.	An electric motor is rated 1.5 KW 250V.Calculate a)current flowing into the motor b)energy consumed by it in one second c)the time in which it will consume 90 kWh of energy
Answer» An electric motor is rated 1.5 KW 250V.Calculate a)current flowing into the motor b)energy consumed by it in one second c)the time in which it will consume 90 kWh of energy

Discussion

44.	On what factors does centre of gravity depends ?
Answer» On what factors does centre of gravity depends ?

Discussion

45.	Why do metals conduct electricity?
Answer» Why do metals conduct electricity?

Discussion

46.	Why does a magnetic does not intersect.....If it doesn't intersect how will the compass will directs in two direction and what is the reason behind it ??
Answer» Why does a magnetic does not intersect.....If it doesn't intersect how will the compass will directs in two direction and what is the reason behind it ??

Discussion

47.	(a) The diagram shown a bar magnet surrounded by four plotting compasses. Copy the diagram and mark in it the direction of the compass needle for each of the cases B, C and D. (b) Which is the north pole, X or Y?
Answer» (a) The diagram shown a bar magnet surrounded by four plotting compasses. Copy the diagram and mark in it the direction of the compass needle for each of the cases B, C and D. (b) Which is the north pole, X or Y?

47.

(a) The diagram shown a bar magnet surrounded by four plotting compasses. Copy the diagram and mark in it the direction of the compass needle for each of the cases B, C and D. (b) Which is the north pole, X or Y?

Answer»

(a) The diagram shown a bar magnet surrounded by four plotting compasses. Copy the diagram and mark in it the direction of the compass needle for each of the cases B, C and D.

(b) Which is the north pole, X or Y?

Discussion

48.	Current produced in a conductor when it moves perpendicular to magnetic field, is known as
Answer» Current produced in a conductor when it moves perpendicular to magnetic field, is known as

Discussion

49.	A lens forms a real image 3 cm high of an object 1 cm high. If the separation of object and image is 15 cm, find the focal length of the lens.
Answer» A lens forms a real image 3 cm high of an object 1 cm high. If the separation of object and image is 15 cm, find the focal length of the lens.

Discussion

50.	(a) Define electirc current. What is the SI unit of electric current. (b) One coulomb of charge flows through any cross-section of a conductor in 1 second. What is the current flowing through the conductor? (c) Which instrument is used to measure electric current ? How should it be connected in a circuit? (d) What is the conventional direction of the flow of electric current ? How does it differ from te direction of flow of electron? (e) A flash of lightning carries 10 C of charge which flows for 0.01 s. What is the current? If the voltage is 10 MV, What is the energy?
Answer» (a) Define electirc current. What is the SI unit of electric current. (b) One coulomb of charge flows through any cross-section of a conductor in 1 second. What is the current flowing through the conductor? (c) Which instrument is used to measure electric current ? How should it be connected in a circuit? (d) What is the conventional direction of the flow of electric current ? How does it differ from te direction of flow of electron? (e) A flash of lightning carries 10 C of charge which flows for 0.01 s. What is the current? If the voltage is 10 MV, What is the energy?

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A cell has an emf 1.5 V. When connected across an external resistance of 2Ω, the terminal potential difference forces to 1V. The internal resistance of the cell is

Derive of mirror formula and lenses formula.

Discuss the Chipko Movement along with the conditions under which it started and its implications.

In which of the following cases, the flow of electric current is maximum?

I want a daily examples of image formed under the object by the concept of concave and convex mirror

Who and how was the gravitational constant G measured?

A small ball 'A' of mass 'm' is attached rigidly to the end of a light rod of length 'd'. The structure rotates about an axis perpendicular to the rod and passing through its other end with an angular velocity 'ω'. Calculate the angular momentum of the system about this axis?

A current carrying conductor placed in magnetic field experiences a force. The amount of force experienced by a current carrying conductor in a magnetic field can be increased by:

Which defect of vision can be rectified : (a) by using a concave lens ? (b) by using a convex lens ?

Which of the following is not a fossil source of energy? (a) kerosene oil (b) cow-dung cakes (c) CNG (d) coal

What is the capacitance of a cylindrical capacitor?

A cannon of mass 1000 kg can fire a bolt of 20 kg with a muzzle velocity (the relative velocity between the cannon and the bolt) of 300 m/s. If the cannon is free to move, the backward velocity of cannon after the bolt is fired will be

Machenicnism of light?

Water in a pond appears to be only three - quarter of its actual depth. What property of light is responsible for this observation?

List 4 characterestcha of image formed by concave mirror

A current of 0.43 A is flowing through a wire of thickness 2 cm. If there are 1018 electrons per cm3 of the wire, calculate the drift velocity of electrons in ms−1. Take the electron charge as 1.6×10−19 C.

Calculate the refractive index of the medium Y, when a light ray enters from air at an angle ∠i=45∘, and ∠r=30∘? 0.7

If two mirrors are kept at 60∘ to each other, then the number of images formed by them is____.

Why is a normal eye not able to see clearly the objects placed closer than 25cm? [3 MARKS]

Why is electric potential zero at infinity?

A man's speed with the current is 15 km/hr and the speed of the current is 2.5 km/hr. The man's speed against the current is

Find out the image position formed by concave mirror, considering the image formed by plane mirror as an object for concave mirror.

3.(C) How does the velocity of light vary with change in the optical density of the media?

When a body is deformed, its centre of gravity

The net resistance of an ammeter should be small to ensure that:

Generally, women have a shriller voice than men, this is because they produce a sound which has higher:

When an object is placed 20 cm from a concave mirror, a real image magnified three times is formed. Find : (a) the focal length of the mirror. (b) Where must the object be placed to give a virtual image three times the height of the object ?

Two resistances R1 and R2 are joined with two batteries of emf E1 and E2. If E2 is short circuited, the current through R1 is

State and explain the New Cartesian Sign Convention for spherical lenses.

The angle of reflection is equal to the angle of incidence : (a) always (b) sometimes (c) under special conditions (d) never

How is coal gas obtained? Enlist its uses.

What should be the minimum wind speed for the satisfactory working of a wind-powered electric generator?

OA is an object with height 4 cm and O'A' is the image of the object. Find the image height and nature of the image formed.

State and explain the Clock face rule for determining the polarities of a circular wire carrying current.

What is a spehirical mirror ?

An electric charge in uniform motion produces :

An electron in an atom:

How can we define electric potential in a simple way?

An electric motor is rated 1.5 KW 250V.Calculate a)current flowing into the motor b)energy consumed by it in one second c)the time in which it will consume 90 kWh of energy

On what factors does centre of gravity depends ?

Why do metals conduct electricity?

Why does a magnetic does not intersect.....If it doesn't intersect how will the compass will directs in two direction and what is the reason behind it ??

(a) The diagram shown a bar magnet surrounded by four plotting compasses. Copy the diagram and mark in it the direction of the compass needle for each of the cases B, C and D. (b) Which is the north pole, X or Y?

Current produced in a conductor when it moves perpendicular to magnetic field, is known as

A lens forms a real image 3 cm high of an object 1 cm high. If the separation of object and image is 15 cm, find the focal length of the lens.