16569 + Interview Questions in Physics

1.	133.a ball is drop from height of 20m above surface of water in lake. Refractive index of water is 4/3.A fish inside lake,in line of fall of ball,is looking at ball.At an instant,when ball is 12.8m above water surface , the fish see speed of ball as
Answer» 133.a ball is drop from height of 20m above surface of water in lake. Refractive index of water is 4/3.A fish inside lake,in line of fall of ball,is looking at ball.At an instant,when ball is 12.8m above water surface , the fish see speed of ball as

Discussion

2.	what is equilibirium ?
Answer» what is equilibirium ?

Discussion

3.	Suggest four steps that can be taken while construction buildings to avoid problems that may occur due to multiple reflection of sound
Answer» Suggest four steps that can be taken while construction buildings to avoid problems that may occur due to multiple reflection of sound

Discussion

4.	If 92U206 undergoes successively 8 α - decays and 6 β - decays, then resulting nucleus is [CBSE PMT 2002]
Answer» If $_{92} U^{206}$ undergoes successively 8 $α$ - decays and 6 $β$ - decays, then resulting nucleus is [CBSE PMT 2002]

Discussion

5.	wheel wehose moment of inertia is 12 kgm^2 has a initial angular velocity of 40 rad/s a constant torque of 20nm act on wheel thetime in which whell is accelerated 100 rad /s
Answer» wheel wehose moment of inertia is 12 kgm^2 has a initial angular velocity of 40 rad/s a constant torque of 20nm act on wheel thetime in which whell is accelerated 100 rad /s

Discussion

6.	{ 108. A spherical shell of radius }R and uniformly charged }}{ with charge }Q is rotating about its axis with frequency }f} Find the magnetic moment of the sphere.
Answer» { 108. A spherical shell of radius }R and uniformly charged }}{ with charge }Q is rotating about its axis with frequency }f} Find the magnetic moment of the sphere.

Discussion

7.	42.A long solenoid wire of radius 'a' carries a steady current i.The Current is uniformly distributed across its cross section .The ratio of magnetic field at a/2 and 2a is
Answer» 42.A long solenoid wire of radius 'a' carries a steady current i.The Current is uniformly distributed across its cross section .The ratio of magnetic field at a/2 and 2a is

Discussion

8.	A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is (i) pushed into the coil?
Answer» A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is (i) pushed into the coil?

Discussion

9.	The variation of deviation with incidence angle is unsymmetrical
Answer» The variation of deviation with incidence angle is unsymmetrical

Discussion

10.	Name some devices in which electric motors are used?
Answer» Name some devices in which electric motors are used?

Discussion

11.	Pure rolling is equivalent to the pure rotation about the instantaneous axis of rotation. Explain the statement with the help of a suitable diagram.
Answer» Pure rolling is equivalent to the pure rotation about the instantaneous axis of rotation. Explain the statement with the help of a suitable diagram.

Discussion

12.	what is the effect of shape of earth on the value of g?
Answer» what is the effect of shape of earth on the value of g?

Discussion

13.	A 10 D lens is used as a magnifier. Where should an object be placed to obtain maximum angular magnification for a normal eye?
Answer» A $10 D$ lens is used as a magnifier. Where should an object be placed to obtain maximum angular magnification for a normal eye?

Discussion

14.	What is the commercial unit of energy? What type of wiring is done in your house?
Answer» What is the commercial unit of energy? What type of wiring is done in your house?

Discussion

15.	Given below are some famous numbers associated with electromagnetic radiations in different contexts in physics. State the part of the electromagnetic spectrum to which each belongs. (a) 21 cm (wavelength emitted by atomic hydrogen in interstellar space). (b) 1057 MHz (frequency of radiation arising from two close energy levels in hydrogen; known as Lamb shift). (c) 2.7 K [temperature associated with the isotropic radiation filling all space-thought to be a relic of the ‘big-bang’ origin of the universe]. (d) 5890 Å - 5896 Å [double lines of sodium] (e) 14.4 keV [energy of a particular transition in 57Fe nucleus associated with a famous high resolution spectroscopic method (Mössbauer spectroscopy)].
Answer» Given below are some famous numbers associated with electromagnetic radiations in different contexts in physics. State the part of the electromagnetic spectrum to which each belongs. (a) 21 cm (wavelength emitted by atomic hydrogen in interstellar space). (b) 1057 MHz (frequency of radiation arising from two close energy levels in hydrogen; known as Lamb shift). (c) 2.7 K [temperature associated with the isotropic radiation filling all space-thought to be a relic of the ‘big-bang’ origin of the universe]. (d) 5890 Å - 5896 Å [double lines of sodium] (e) 14.4 keV [energy of a particular transition in 57Fe nucleus associated with a famous high resolution spectroscopic method (Mössbauer spectroscopy)].

Discussion

16.	Transformer works on
Answer» Transformer works on

Discussion

17.	Light is incident on a parallel sided rectangular glass slab at 45 degrees on one face AB of the slab and emerges from the opposite face CD. What is the distance traveled by the light ray inside the glass if the thickness AC of the glass slab is 4cm and the refractive index of the material of the glass slab is √2?
Answer» Light is incident on a parallel sided rectangular glass slab at 45 degrees on one face AB of the slab and emerges from the opposite face CD. What is the distance traveled by the light ray inside the glass if the thickness AC of the glass slab is 4cm and the refractive index of the material of the glass slab is $\sqrt{2}$ ?

Discussion

18.	44 How many miles of electron weigh one kilogram ?1.6.022×10^232.1/9.108×10^313.6.023/9.108×10^544.1/9.108×6.023×10^8
Answer» 44 How many miles of electron weigh one kilogram ?1.6.022×10^232.1/9.108×10^313.6.023/9.108×10^544.1/9.108×6.023×10^8

Discussion

19.	What is the importance of the universal law of Gravitation?
Answer» What is the importance of the universal law of Gravitation?

Discussion

20.	Define Ohms law.
Answer» Define Ohms law.

Discussion

21.	What are the advantages of solar cell?
Answer» What are the advantages of solar cell?

Discussion

22.	An electric motor works making use of
Answer» An electric motor works making use of

Discussion

23.	A 6 V battery is connected across a lamp whose resistance is 20 Ω. Calculate the value of the extra resistance which must be used in the circuit to get 0.25 A current in the circuit.
Answer» A $6 V$ battery is connected across a lamp whose resistance is $20 Ω$ . Calculate the value of the extra resistance which must be used in the circuit to get $0.25 A$ current in the circuit.

Discussion

24.	What happens to the force between two objects, if(i) the mass of one object is doubled?(ii) the distance between the objects is doubled and tripled?(iii) the masses of both objects are doubled?
Answer» What happens to the force between two objects, if (i) the mass of one object is doubled? (ii) the distance between the objects is doubled and tripled? (iii) the masses of both objects are doubled?

Discussion

25.	Question 5 During an experiment, a signal from a spaceship reached the ground station in five minutes. What was the distance of the spaceship from the ground station? The signal travels at the speed of light, that is, 3×108ms−1
Answer» Question 5 During an experiment, a signal from a spaceship reached the ground station in five minutes. What was the distance of the spaceship from the ground station? The signal travels at the speed of light, that is, $3 \times 10^{8} m s^{- 1}$

Discussion

26.	The angular velocity of a body is \overset⇀ω =2i+j+5k rad/s under a torqueζ=5i+2j+3k N-m acting on it. The ins†an†an eous rotational power is Options: a- 27 W b- 10 W c-18 W d-24 W
Answer» The angular velocity of a body is \overset⇀ω =2i+j+5k rad/s under a torqueζ=5i+2j+3k N-m acting on it. The ins†an†an eous rotational power is Options: a- 27 W b- 10 W c-18 W d-24 W

Discussion

27.	The combination of convex lens focal length is equal to 18 cm and I thin concave lens focal length is equal to 9 cm is Options A concave lens f is equal to 18 centimetre A convex lens f is equal to 180 cm A convex lens f is equal to 6 CM A concave lens f is equal to 6 centimetre
Answer» The combination of convex lens focal length is equal to 18 cm and I thin concave lens focal length is equal to 9 cm is Options A concave lens f is equal to 18 centimetre A convex lens f is equal to 180 cm A convex lens f is equal to 6 CM A concave lens f is equal to 6 centimetre

Discussion

28.	What is full wave rectifier?
Answer» What is full wave rectifier?

Discussion

29.	ntThe change of energy on freezing 1.0 kg of liquid water at 0 degree celcius and one atm . in Kj/kg isn ntn
Answer» ntThe change of energy on freezing 1.0 kg of liquid water at 0 degree celcius and one atm . in Kj/kg isn ntn

Discussion

30.	With which tree Amrita Devi Bishnoi is associated? (a) khajoor (b) khejrali (c) khejri (d) keekar
Answer» With which tree Amrita Devi Bishnoi is associated? (a) khajoor (b) khejrali (c) khejri (d) keekar

Discussion

31.	The process of conversion of liquid to vapour at any temperature is called:
Answer» The process of conversion of liquid to vapour at any temperature is called:

Discussion

32.	An antimony ball of volume 15 cm3 is heated to 210 ∘C which caused the volume to become 15.045 cm3, if γ for antimony is 15×10−6 ∘C−1, what is the initial temperature of the ball?
Answer» An antimony ball of volume $15 {cm}^{3}$ is heated to $210^{\circ} C$ which caused the volume to become $15.045 {cm}^{3}$ , if $γ$ for antimony is $15 \times 10^{- 6}^{\circ} C^{- 1}$ , what is the initial temperature of the ball?

Discussion

33.	An α− particle of mass m suffers one-dimensional elastic collision with a nucleus at rest of unknown mass. It is scattered directly backwards losing 64 % of its initial kinetic energy. The mass of the nucleus is
Answer» An $α -$ particle of mass $m$ suffers one-dimensional elastic collision with a nucleus at rest of unknown mass. It is scattered directly backwards losing $64 %$ of its initial kinetic energy. The mass of the nucleus is

Discussion

34.	Two equi- convex lenses A and B have same focal length, but radii of curvature differ such that RA=0.9 RB. If μA=1.63, then find μB.(μA→ Refractive index of lens A and μB→ Refractive index of lens B)
Answer» Two equi- convex lenses $A$ and $B$ have same focal length, but radii of curvature differ such that $R_{A} = 0.9$ $R_{B}$ . If $μ_{A} = 1.63,$ then find $μ_{B} .$ $($ $μ_{A} \to$ Refractive index of lens $A$ and $μ_{B} \to$ Refractive index of lens $B$ $)$

Discussion

35.	Two resistances of 100 Ω and 0 Ω are connected in parallel. The overall resistance will be___Ω.
Answer» Two resistances of 100 Ω and 0 Ω are connected in parallel. The overall resistance will be___Ω.

Discussion

36.	A plano convex glass lens (μg=32) of radius of curvature R=10 cm is placed at a distance of b from a concave lens of focal length 20 cm. What should be the distance a of a point object O from the plano convex lens, such that the position of final image is always at same distance from concave lens?
Answer» A plano convex glass lens $(μ_{g} = \frac{3}{2})$ of radius of curvature $R = 10 cm$ is placed at a distance of $b$ from a concave lens of focal length $20 cm$ . What should be the distance $a$ of a point object $O$ from the plano convex lens, such that the position of final image is always at same distance from concave lens?

Discussion

37.	An equiconvex lens of glass (μ=3/2), with each of its surfaces having radius of curvature 20cm, is placed with air in the object space and water in the image space. Find the ratio of its focal length with reference to its face placed in air.
Answer» An equiconvex lens of glass (μ=3/2), with each of its surfaces having radius of curvature 20cm, is placed with air in the object space and water in the image space. Find the ratio of its focal length with reference to its face placed in air.

Discussion

38.	A 44 MVA, 10.5 kV, Y-connected three-phase salient pole synchronous generator has Xd=1.83Ω and Xq=1.21Ω. It delivers the rated load at 0.8 p.f. lagging. The armature resistance is negligible, the load angle of the given alternator is ______ degrees (upto two decimal places).16.69
Answer» A 44 MVA, 10.5 kV, Y-connected three-phase salient pole synchronous generator has $X_{d} = 1.83 Ω$ and $X_{q} = 1.21 Ω$ . It delivers the rated load at 0.8 p.f. lagging. The armature resistance is negligible, the load angle of the given alternator is ______ degrees (upto two decimal places). 16.69

Discussion

39.	Two forces F1=5 N and F2=8 N acting at points A and B on a rod pivoted at a point O, such that OA = 2 m and OB = 4 m. Calculate the total moment of the two forces about O.
Answer» Two forces $F_{1} = 5 N$ and $F_{2} = 8 N$ acting at points A and B on a rod pivoted at a point O, such that OA = $2 m$ and OB = $4 m$ . Calculate the total moment of the two forces about O.

39.

Two forces F1=5 N and F2=8 N acting at points A and B on a rod pivoted at a point O, such that OA = 2 m and OB = 4 m. Calculate the total moment of the two forces about O.

Answer»

Two forces $F_{1} = 5 N$ and $F_{2} = 8 N$ acting at points A and B on a rod pivoted at a point O, such that OA = $2 m$ and OB = $4 m$ . Calculate the total moment of the two forces about O.

Discussion

40.	A key of a mechanical piano is struck gently. The same key is then struck again, but much harder this time. In the second case:
Answer» A key of a mechanical piano is struck gently. The same key is then struck again, but much harder this time. In the second case:

Discussion

41.	A hydrogen atom is excited from n=1 to n=2 energy state. What is the wavelength of the radiation emitted by the atom when it goes back to its ground state ? (hc=12431 eV ∘A)
Answer» A hydrogen atom is excited from $n = 1$ to $n = 2$ energy state. What is the wavelength of the radiation emitted by the atom when it goes back to its ground state ? $(h c = 12431 eV \circ A)$

Discussion

42.	ntnttA potentiometer circuit has been set up for finding the internal resistance of a given cell. The main battery, used across the potentiometer wire, has an emf of 2.0 V and a negligible internal resistance. The potentiometer wire itself is 4m long. When the resistance, R, connected across the given cell, has values of. (i) infinity (ii) 9.5 Ω the 'balancing lengths', on the potentiometer wire are found to be 3 m and 2.85 m, respectively. The value of internal resistance of the cell isnn nt ntt nttt(1) 0.25 Ω (2) 0.95 Ωnttt(3) 0.5 Ω (4) 0.75 Ωntnn ntn
Answer» ntnttA potentiometer circuit has been set up for finding the internal resistance of a given cell. The main battery, used across the potentiometer wire, has an emf of 2.0 V and a negligible internal resistance. The potentiometer wire itself is 4m long. When the resistance, R, connected across the given cell, has values of. (i) infinity (ii) 9.5 Ω the 'balancing lengths', on the potentiometer wire are found to be 3 m and 2.85 m, respectively. The value of internal resistance of the cell isnn nt ntt nttt(1) 0.25 Ω (2) 0.95 Ωnttt(3) 0.5 Ω (4) 0.75 Ωntnn ntn

Discussion

43.	Question 3Which sources produce alternating current?
Answer» Question 3 Which sources produce alternating current?

Discussion

44.	How to find maximum wave no.?
Answer» How to find maximum wave no.?

Discussion

45.	Electromagnetic radiation travels through vacuum at a speed of __________ m/s.
Answer» Electromagnetic radiation travels through vacuum at a speed of __________ m/s.

Discussion

46.	A wire 1 m long has a resistances of 1Ω. If it is uniformly stretched, so that its length increases by 25%, then its resistance will increase by:
Answer» A wire 1 m long has a resistances of 1Ω. If it is uniformly stretched, so that its length increases by 25%, then its resistance will increase by:

Discussion

47.	A mass of 50 g of a certain metal at 150∘C is immersed in 100 g of water at 11∘C. The final temperature is 20∘C. Calculate the specific heat capacity of the metal. Assume that the specific heat capacity of water is 4.2 J g−1 K−1.
Answer» A mass of 50 g of a certain metal at $150^{\circ} C$ is immersed in 100 g of water at $11^{\circ} C$ . The final temperature is $20^{\circ} C$ . Calculate the specific heat capacity of the metal. Assume that the specific heat capacity of water is 4.2 J $g^{- 1} K^{- 1}$ .

Discussion

48.	(a) Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?(b) Draw a diagram to show the magnetic field lines around a bar magnet. List any two properties of magnetic field lines.
Answer» (a) Why is a series arrangement not used for connecting domestic electrical appliances in a circuit? (b) Draw a diagram to show the magnetic field lines around a bar magnet. List any two properties of magnetic field lines.

Discussion

49.	Name the constitutents of biogas.
Answer» Name the constitutents of biogas.

Discussion

50.	State two factors affecting the turning effect of a force.
Answer» State two factors affecting the turning effect of a force.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

133.a ball is drop from height of 20m above surface of water in lake. Refractive index of water is 4/3.A fish inside lake,in line of fall of ball,is looking at ball.At an instant,when ball is 12.8m above water surface , the fish see speed of ball as

what is equilibirium ?

Suggest four steps that can be taken while construction buildings to avoid problems that may occur due to multiple reflection of sound

If 92U206 undergoes successively 8 α - decays and 6 β - decays, then resulting nucleus is [CBSE PMT 2002]

wheel wehose moment of inertia is 12 kgm^2 has a initial angular velocity of 40 rad/s a constant torque of 20nm act on wheel thetime in which whell is accelerated 100 rad /s

{ 108. A spherical shell of radius }R and uniformly charged }}{ with charge }Q is rotating about its axis with frequency }f} Find the magnetic moment of the sphere.

42.A long solenoid wire of radius 'a' carries a steady current i.The Current is uniformly distributed across its cross section .The ratio of magnetic field at a/2 and 2a is

A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is (i) pushed into the coil?

The variation of deviation with incidence angle is unsymmetrical

Name some devices in which electric motors are used?

Pure rolling is equivalent to the pure rotation about the instantaneous axis of rotation. Explain the statement with the help of a suitable diagram.

what is the effect of shape of earth on the value of g?

A 10 D lens is used as a magnifier. Where should an object be placed to obtain maximum angular magnification for a normal eye?

What is the commercial unit of energy? What type of wiring is done in your house?

Transformer works on

44 How many miles of electron weigh one kilogram ?1.6.022×10^232.1/9.108×10^313.6.023/9.108×10^544.1/9.108×6.023×10^8

What is the importance of the universal law of Gravitation?

Define Ohms law.

What are the advantages of solar cell?

An electric motor works making use of

A 6 V battery is connected across a lamp whose resistance is 20 Ω. Calculate the value of the extra resistance which must be used in the circuit to get 0.25 A current in the circuit.

What happens to the force between two objects, if(i) the mass of one object is doubled?(ii) the distance between the objects is doubled and tripled?(iii) the masses of both objects are doubled?

Question 5 During an experiment, a signal from a spaceship reached the ground station in five minutes. What was the distance of the spaceship from the ground station? The signal travels at the speed of light, that is, 3×108ms−1

The angular velocity of a body is \overset⇀ω =2i+j+5k rad/s under a torqueζ=5i+2j+3k N-m acting on it. The ins†an†an eous rotational power is Options: a- 27 W b- 10 W c-18 W d-24 W

The combination of convex lens focal length is equal to 18 cm and I thin concave lens focal length is equal to 9 cm is Options A concave lens f is equal to 18 centimetre A convex lens f is equal to 180 cm A convex lens f is equal to 6 CM A concave lens f is equal to 6 centimetre

What is full wave rectifier?

ntThe change of energy on freezing 1.0 kg of liquid water at 0 degree celcius and one atm . in Kj/kg isn ntn

With which tree Amrita Devi Bishnoi is associated? (a) khajoor (b) khejrali (c) khejri (d) keekar

The process of conversion of liquid to vapour at any temperature is called:

An antimony ball of volume 15 cm3 is heated to 210 ∘C which caused the volume to become 15.045 cm3, if γ for antimony is 15×10−6 ∘C−1, what is the initial temperature of the ball?

An α− particle of mass m suffers one-dimensional elastic collision with a nucleus at rest of unknown mass. It is scattered directly backwards losing 64 % of its initial kinetic energy. The mass of the nucleus is

Two equi- convex lenses A and B have same focal length, but radii of curvature differ such that RA=0.9 RB. If μA=1.63, then find μB.(μA→ Refractive index of lens A and μB→ Refractive index of lens B)

Two resistances of 100 Ω and 0 Ω are connected in parallel. The overall resistance will be___Ω.

A plano convex glass lens (μg=32) of radius of curvature R=10 cm is placed at a distance of b from a concave lens of focal length 20 cm. What should be the distance a of a point object O from the plano convex lens, such that the position of final image is always at same distance from concave lens?

An equiconvex lens of glass (μ=3/2), with each of its surfaces having radius of curvature 20cm, is placed with air in the object space and water in the image space. Find the ratio of its focal length with reference to its face placed in air.

A 44 MVA, 10.5 kV, Y-connected three-phase salient pole synchronous generator has Xd=1.83Ω and Xq=1.21Ω. It delivers the rated load at 0.8 p.f. lagging. The armature resistance is negligible, the load angle of the given alternator is ______ degrees (upto two decimal places).16.69

Two forces F1=5 N and F2=8 N acting at points A and B on a rod pivoted at a point O, such that OA = 2 m and OB = 4 m. Calculate the total moment of the two forces about O.

A key of a mechanical piano is struck gently. The same key is then struck again, but much harder this time. In the second case:

A hydrogen atom is excited from n=1 to n=2 energy state. What is the wavelength of the radiation emitted by the atom when it goes back to its ground state ? (hc=12431 eV ∘A)

Question 3Which sources produce alternating current?

How to find maximum wave no.?

Electromagnetic radiation travels through vacuum at a speed of __________ m/s.

A wire 1 m long has a resistances of 1Ω. If it is uniformly stretched, so that its length increases by 25%, then its resistance will increase by:

A mass of 50 g of a certain metal at 150∘C is immersed in 100 g of water at 11∘C. The final temperature is 20∘C. Calculate the specific heat capacity of the metal. Assume that the specific heat capacity of water is 4.2 J g−1 K−1.

(a) Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?​(b) Draw a diagram to show the magnetic field lines around a bar magnet. List any two properties of magnetic field lines.

Name the constitutents of biogas.

State two factors affecting the turning effect of a force.

(a) Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?(b) Draw a diagram to show the magnetic field lines around a bar magnet. List any two properties of magnetic field lines.