16569 + Interview Questions in Physics

1.	Why do rays from object placed at infinity are always parallel?
Answer» Why do rays from object placed at infinity are always parallel?

Discussion

2.	The angle of the prism is 30∘. The rays incident at 60∘ on one refracting surface suffers a total deviation of 30∘. Find the angle of emergence.
Answer» The angle of the prism is $30^{\circ}$ . The rays incident at $60^{\circ}$ on one refracting surface suffers a total deviation of $30^{\circ}$ . Find the angle of emergence.

Discussion

3.	If the ammeter in the given circuit reads 2 A, the value of resistance R is
Answer» If the ammeter in the given circuit reads 2 A, the value of resistance R is

Discussion

4.	Why Issac Newton kept the second prism inverted in recombination of the spectrum of white light?
Answer» Why Issac Newton kept the second prism inverted in recombination of the spectrum of white light?

Discussion

5.	70. With increase in temperature Ecell will decrease , how?
Answer» 70. With increase in temperature Ecell will decrease , how?

Discussion

6.	The equivalent resistance between X and Y is
Answer» The equivalent resistance between $X$ and $Y$ is

Discussion

7.	Question 3 If it has rained 276mm in the last 3 days, how many cm of rain will fall in one full week (7 days)? Assume that the rain continues to fall at the same rate.
Answer» Question 3 If it has rained 276mm in the last 3 days, how many cm of rain will fall in one full week (7 days)? Assume that the rain continues to fall at the same rate.

7.

Question 3 If it has rained 276mm in the last 3 days, how many cm of rain will fall in one full week (7 days)? Assume that the rain continues to fall at the same rate.

Answer»

Question 3

If it has rained 276mm in the last 3 days, how many cm of rain will fall in one full week (7 days)? Assume that the rain continues to fall at the same rate.

Discussion

8.	in case of galvanic cell, it is said that zinc goes into the solution in the form of Zn^{2+} and loses two electrons , copper comes out of the solution and discharged at the electrode , what force helps them to do so , is this because of any electric force, if yes then what is the source of this force
Answer» in case of galvanic cell, it is said that zinc goes into the solution in the form of Zn^{2+} and loses two electrons , copper comes out of the solution and discharged at the electrode , what force helps them to do so , is this because of any electric force, if yes then what is the source of this force

Discussion

9.	A ray of light is incident on a glass-water interface at an angle i, it merges finally parallel to the surface of the water as shown in the figure, the value of μg would be:
Answer» A ray of light is incident on a glass-water interface at an angle i, it merges finally parallel to the surface of the water as shown in the figure, the value of $μ_{g}$ would be:

Discussion

10.	24. The binding energy per nucleon for C- 12 is 7.68 MeV and that for C-13 is 7.4 MeV. calculate the energy required to remove a neutron from C-13.
Answer» 24. The binding energy per nucleon for C- 12 is 7.68 MeV and that for C-13 is 7.4 MeV. calculate the energy required to remove a neutron from C-13.

Discussion

11.	34. When a beam of light goes from denser medium (N1) to rarer medium (N2), then it is generally observed that magnitude of angle of incidence is half that of angle of refraction. Then magnitude of incident angle will be (here N=N2/N1)
Answer» 34. When a beam of light goes from denser medium (N1) to rarer medium (N2), then it is generally observed that magnitude of angle of incidence is half that of angle of refraction. Then magnitude of incident angle will be (here N=N2/N1)

Discussion

12.	If 150 J s−1 is required for an appliance to run, what is the power consumed by it, if it is operated at 240 V?
Answer» If $150 {J s}^{- 1}$ is required for an appliance to run, what is the power consumed by it, if it is operated at $240 V$ ?

Discussion

13.	Charge on a capacitor decreases to n times to its initial value in time T when it discharges through a circuit with a time constant
Answer» Charge on a capacitor decreases to n times to its initial value in time T when it discharges through a circuit with a time constant

Discussion

14.	A planet moving along an elliptical orbit is closest to the sun at a distance r1 and farthest away at a distance of r2. If v1 and v2 are the linear velocities at these points respectively, then the ratio v1v2 is
Answer» A planet moving along an elliptical orbit is closest to the sun at a distance $r_{1}$ and farthest away at a distance of $r_{2}$ . If $v_{1}$ and $v_{2}$ are the linear velocities at these points respectively, then the ratio $\frac{v_{1}}{v_{2}}$ is

Discussion

15.	The specific latent heat of fusion of lead is 5.9 kcalkg-1. A block of lead at its melting point needs 177 kcal of heat for complete melting. What is the mass of the lead?
Answer» The specific latent heat of fusion of lead is 5.9 kcalkg^-1. A block of lead at its melting point needs 177 kcal of heat for complete melting. What is the mass of the lead?

Discussion

16.	Which is true about Boyle's Law?
Answer» Which is true about Boyle's Law?

Discussion

17.	If n equal resistances are first connected in series and then connected in parallel, the ratio of the maximum to the minimum resistance is
Answer» If n equal resistances are first connected in series and then connected in parallel, the ratio of the maximum to the minimum resistance is

Discussion

18.	89. An earth's satellite is moving in a circular orbit with a uniform speed v.If the gravitational force of the earth suddenly disappears,the satellite will 1) vanish into outer space 2) continue to move with velocity v in original orbit 3) fall down with increasing velocity 4) fly off tangentially from the orbit with velocity v
Answer» 89. An earth's satellite is moving in a circular orbit with a uniform speed v.If the gravitational force of the earth suddenly disappears,the satellite will 1) vanish into outer space 2) continue to move with velocity v in original orbit 3) fall down with increasing velocity 4) fly off tangentially from the orbit with velocity v

Discussion

19.	While taking the reading of meter,what should be the position of eye
Answer» While taking the reading of meter,what should be the position of eye

Discussion

20.	70. First excitation potential of H atom is (a) 10.2 eV (b) 3.4 eV (c) 0 (d) -3.4 eV
Answer» 70. First excitation potential of H atom is (a) 10.2 eV (b) 3.4 eV (c) 0 (d) -3.4 eV

Discussion

21.	19. A body is fired with velocity V (greater than orbital velocity and less than escape velocity) at an angle 30 degree with the radius vector. If at highest point the speed of the body is v/4, then the maximum height (from the surface of earth) attained by the body is equal to (R=radius of earth) (A) v square/8g (B) 2R (C) (?2)RR
Answer» 19. A body is fired with velocity V (greater than orbital velocity and less than escape velocity) at an angle 30 degree with the radius vector. If at highest point the speed of the body is v/4, then the maximum height (from the surface of earth) attained by the body is equal to (R=radius of earth) (A) v square/8g (B) 2R (C) (?2)RR

Discussion

22.	A wire of length l having tension T and radius r vibrates with natural frequency f. Another wire of same metal with length 2l having tension 2T and radius 2r will vibrate with frequenc
Answer» A wire of length l having tension T and radius r vibrates with natural frequency f. Another wire of same metal with length 2l having tension 2T and radius 2r will vibrate with frequenc

Discussion

23.	a long straight wire is carrying a current of 25 A. A square loop of side length 10cm carrying a current of 15 A is placed 2 cm from the wire as shown in the figure. The force on the loop i
Answer» a long straight wire is carrying a current of 25 A. A square loop of side length 10cm carrying a current of 15 A is placed 2 cm from the wire as shown in the figure. The force on the loop i

Discussion

24.	Calculate the resolving power of a microscope with cone angle of light falling on the objective equal to 60∘. Take λ=600 nm and the refractive index of transparent medium between the object and the objective lens of the microscope, μ=4/3.
Answer» Calculate the resolving power of a microscope with cone angle of light falling on the objective equal to $60^{\circ} .$ Take $λ = 600 nm$ and the refractive index of transparent medium between the object and the objective lens of the microscope, $μ = 4 / 3 .$

Discussion

25.	ray of light is incident normally on one of thefaces of a prism apex angle 30^° and refractiveindex 2. The angle of deviation of the ray is:
Answer» ray of light is incident normally on one of thefaces of a prism apex angle 30^° and refractiveindex 2. The angle of deviation of the ray is:

Discussion

26.	If a shunt of value (1/n) times the galvanometer resis†an ce is applied to moving coil galvanometer, by what factor will its current sensitivity will change?
Answer» If a shunt of value (1/n) times the galvanometer resis†an ce is applied to moving coil galvanometer, by what factor will its current sensitivity will change?

Discussion

27.	The focal length of a thin convex lens for red and blue rays are 100cm and 96.8cm resp. The dispersive power of the material of the lens is
Answer» The focal length of a thin convex lens for red and blue rays are 100cm and 96.8cm resp. The dispersive power of the material of the lens is

Discussion

28.	The heat produced on complete combustion of 10 g of a fuel could raise the temperature of 2.5 kg of water from 40∘C to80∘C. Calculate the calorific value of fuel, if the specific heat capacity of water was 4.2J/g∘C.
Answer» The heat produced on complete combustion of 10 g of a fuel could raise the temperature of 2.5 kg of water from $40^{\circ} C$ to $80^{\circ} C$ . Calculate the calorific value of fuel, if the specific heat capacity of water was $4.2 J / g^{\circ} C .$

Discussion

29.	There are 5 rooms in a house.Each room has 100W bulb and a 40W tubelight.If every day the bulb is use for 1hour and tubelight is use for 5hours in each room,then what will the cost of total electric energy consumed in 30days when one unit costs Rs.2.5
Answer» There are 5 rooms in a house.Each room has 100W bulb and a 40W tubelight.If every day the bulb is use for 1hour and tubelight is use for 5hours in each room,then what will the cost of total electric energy consumed in 30days when one unit costs Rs.2.5

Discussion

30.	A shell of mass 0.02kg is fired by a gun of mass 100 kg. The muzzle speed of the shell is 80 m s^{-1}.Find the recoil speed of the gun.
Answer» A shell of mass 0.02kg is fired by a gun of mass 100 kg. The muzzle speed of the shell is 80 m s^{-1}.Find the recoil speed of the gun.

Discussion

31.	Question 11The bluish colour of water in deep sea is due to(a) the presence of algae and other plants found in water(b) reflection of sky in water(c) scattering of light(d) absorption of light by the sea
Answer» Question 11 The bluish colour of water in deep sea is due to (a) the presence of algae and other plants found in water (b) reflection of sky in water (c) scattering of light (d) absorption of light by the sea

Discussion

32.	Escape velocity of a body of 1 kg mass on a planet is 100 m/sec. Gravitational Potential energy of the body at the Planet is
Answer» Escape velocity of a body of 1 kg mass on a planet is 100 m/sec. Gravitational Potential energy of the body at the Planet is

Discussion

33.	2 conductors a and b have lengths in ratio 4:3and area of cross section ratio 1:2and resistivities in ratio 2:3 what will be the ratio of the resistance s
Answer» 2 conductors a and b have lengths in ratio 4:3and area of cross section ratio 1:2and resistivities in ratio 2:3 what will be the ratio of the resistance s

Discussion

34.	List four advantages of conserving water.
Answer» List four advantages of conserving water.

Discussion

35.	A potentiometer wire of length 100 cm has a resistance of 10 ohm.It is connected in a series with a resistance and accumulator of EMF 2V and negligible internal resistance .A source of EMF 10 mV is balanced against a length of 40 cm of the potentiometer wire.What is the value of the external resistsnce?
Answer» A potentiometer wire of length 100 cm has a resistance of 10 ohm.It is connected in a series with a resistance and accumulator of EMF 2V and negligible internal resistance .A source of EMF 10 mV is balanced against a length of 40 cm of the potentiometer wire.What is the value of the external resistsnce?

Discussion

36.	A 400 V, 50 Hz, 35 hp, 3-ϕ induction motor is drawing 50 A current at 0.8 power factor lagging. The rotor and stator copper losses are 950 W and 1.5 kW respectively. The friction and windage losses are 1 kW and core losses are 1.2 kW. The value of air gap power is ________ kW.25
Answer» A 400 V, 50 Hz, 35 hp, 3- $ϕ$ induction motor is drawing 50 A current at 0.8 power factor lagging. The rotor and stator copper losses are 950 W and 1.5 kW respectively. The friction and windage losses are 1 kW and core losses are 1.2 kW. The value of air gap power is ________ kW. 25

Discussion

37.	146.Two cells when connected in series are balanced on 6m on a potentiometer.if the polarity of one of these cell is reversed,they balance,on 2m. The ratio of e.m.f of the two cells is?
Answer» 146.Two cells when connected in series are balanced on 6m on a potentiometer.if the polarity of one of these cell is reversed,they balance,on 2m. The ratio of e.m.f of the two cells is?

Discussion

38.	What is meant by amplitude
Answer» What is meant by amplitude

Discussion

39.	For total internal reflection to take place, the angle of incidence i and the refractive index (μ) of the medium must satisfy the inequality
Answer» For total internal reflection to take place, the angle of incidence $i$ and the refractive index ( $μ$ ) of the medium must satisfy the inequality

Discussion

40.	Which of the following options describes the etymology of word “biomass” correctly?
Answer» Which of the following options describes the etymology of word “biomass” correctly?

Discussion

41.	35.During rocket propulsion, gases ejecting with velocity 1 kilometre per second relative to rocket. The rate of fuel consumption is M/10 kilogram per second where m is the instantaneous mass of the rocket. If air resistance varies according to the equation f=0.15mv, then terminal velocity of the rocket is:-
Answer» 35.During rocket propulsion, gases ejecting with velocity 1 kilometre per second relative to rocket. The rate of fuel consumption is M/10 kilogram per second where m is the instantaneous mass of the rocket. If air resistance varies according to the equation f=0.15mv, then terminal velocity of the rocket is:-

Discussion

42.	Two long parallel wires, having zero resistance, are connected to each other by a battery of 1.0 V. The separation between the wires is 0.5 m. A metallic bar of resistance 10 Ω, placed perpendicular to the wires, moves on these wires. A uniform magnetic field of 0.02 T is acting perpendicular to the plane containing the bar and the wires. Find the steady-state velocity of the bar.
Answer» Two long parallel wires, having zero resistance, are connected to each other by a battery of $1.0 V$ . The separation between the wires is $0.5 m$ . A metallic bar of resistance $10 Ω$ , placed perpendicular to the wires, moves on these wires. A uniform magnetic field of $0.02 T$ is acting perpendicular to the plane containing the bar and the wires. Find the steady-state velocity of the bar.

Discussion

43.	Find the radius of gyration of a uniform disc of mass m and radius R about an axis passing tangentially to the disc.
Answer» Find the radius of gyration of a uniform disc of mass m and radius R about an axis passing tangentially to the disc.

Discussion

44.	If mass and radius of the Earth are 6.0×1024 kg and 6.4×106 m respectively, calculate the force exerted by the Earth on a body of mass 1 kg.
Answer» If mass and radius of the Earth are $6.0 \times 10^{24}$ kg and $6.4 \times 10^{6}$ m respectively, calculate the force exerted by the Earth on a body of mass 1 kg.

Discussion

45.	The switching circuit given in the figure can be expressed in binary logic notation as,
Answer» The switching circuit given in the figure can be expressed in binary logic notation as,

Discussion

46.	A 50 kVA, 22 kV/220 V, Δ−Y distribution transformer has a resistance of 1 percent and reactance of 8 percentage.The magnitude of transformer's phase impedance referred to hv side will be ____
Answer» A 50 kVA, 22 kV/220 V, $Δ - Y$ distribution transformer has a resistance of 1 percent and reactance of 8 percentage.The magnitude of transformer's phase impedance referred to hv side will be ____

Discussion

47.	Question 11A successful forest conservation strategy should involve(a) protection of animals at the highest trophic level(b) protection of only consumers(c) protection of only herbivores(d) comprehensive programme to protect all the physical and biological components
Answer» Question 11 A successful forest conservation strategy should involve (a) protection of animals at the highest trophic level (b) protection of only consumers (c) protection of only herbivores (d) comprehensive programme to protect all the physical and biological components

Discussion

48.	The temperature of a thin wire of lead of length 5 cm is raised by 150 ∘C which increases its length by about 0.2 mm. What is the coefficient of cubical expansion of lead?
Answer» The temperature of a thin wire of lead of length $5 cm$ is raised by $150^{\circ} C$ which increases its length by about $0.2 mm$ . What is the coefficient of cubical expansion of lead?

Discussion

49.	A container has N molecules at absolute temperature T . If the number of molecules is doubled but kinetic energy in the box remain same the absolute temperature of gas is
Answer» A container has N molecules at absolute temperature T . If the number of molecules is doubled but kinetic energy in the box remain same the absolute temperature of gas is

Discussion

50.	A metallic rod of mass per unit length 0.5 kg/m is lying horizontally on a smooth inclined plane which makes an angle of 30^° withthe horizontal. The rod is not allowed to slidedown by flowing a current through it when magnetic field of induction 0.25 T is acting on it in the vertical direction. The current flowing inthe rod to keep it stationary is
Answer» A metallic rod of mass per unit length 0.5 kg/m is lying horizontally on a smooth inclined plane which makes an angle of 30^° withthe horizontal. The rod is not allowed to slidedown by flowing a current through it when magnetic field of induction 0.25 T is acting on it in the vertical direction. The current flowing inthe rod to keep it stationary is

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Why do rays from object placed at infinity are always parallel?

The angle of the prism is 30∘. The rays incident at 60∘ on one refracting surface suffers a total deviation of 30∘. Find the angle of emergence.

If the ammeter in the given circuit reads 2 A, the value of resistance R is

Why Issac Newton kept the second prism inverted in recombination of the spectrum of white light?

70. With increase in temperature Ecell will decrease , how?

The equivalent resistance between X and Y is

Question 3 If it has rained 276mm in the last 3 days, how many cm of rain will fall in one full week (7 days)? Assume that the rain continues to fall at the same rate.

A ray of light is incident on a glass-water interface at an angle i, it merges finally parallel to the surface of the water as shown in the figure, the value of μg would be:

24. The binding energy per nucleon for C- 12 is 7.68 MeV and that for C-13 is 7.4 MeV. calculate the energy required to remove a neutron from C-13.

34. When a beam of light goes from denser medium (N1) to rarer medium (N2), then it is generally observed that magnitude of angle of incidence is half that of angle of refraction. Then magnitude of incident angle will be (here N=N2/N1)

If 150 J s−1 is required for an appliance to run, what is the power consumed by it, if it is operated at 240 V?

Charge on a capacitor decreases to n times to its initial value in time T when it discharges through a circuit with a time constant

A planet moving along an elliptical orbit is closest to the sun at a distance r1 and farthest away at a distance of r2. If v1 and v2 are the linear velocities at these points respectively, then the ratio v1v2 is

The specific latent heat of fusion of lead is 5.9 kcalkg-1. A block of lead at its melting point needs 177 kcal of heat for complete melting. What is the mass of the lead?

Which is true about Boyle's Law?

If n equal resistances are first connected in series and then connected in parallel, the ratio of the maximum to the minimum resistance is

While taking the reading of meter,what should be the position of eye

70. First excitation potential of H atom is (a) 10.2 eV (b) 3.4 eV (c) 0 (d) -3.4 eV

A wire of length l having tension T and radius r vibrates with natural frequency f. Another wire of same metal with length 2l having tension 2T and radius 2r will vibrate with frequenc

a long straight wire is carrying a current of 25 A. A square loop of side length 10cm carrying a current of 15 A is placed 2 cm from the wire as shown in the figure. The force on the loop i

Calculate the resolving power of a microscope with cone angle of light falling on the objective equal to 60∘. Take λ=600 nm and the refractive index of transparent medium between the object and the objective lens of the microscope, μ=4/3.

ray of light is incident normally on one of thefaces of a prism apex angle 30^° and refractiveindex 2. The angle of deviation of the ray is:

If a shunt of value (1/n) times the galvanometer resis†an ce is applied to moving coil galvanometer, by what factor will its current sensitivity will change?

The focal length of a thin convex lens for red and blue rays are 100cm and 96.8cm resp. The dispersive power of the material of the lens is

The heat produced on complete combustion of 10 g of a fuel could raise the temperature of 2.5 kg of water from 40∘C to80∘C. Calculate the calorific value of fuel, if the specific heat capacity of water was 4.2J/g∘C.

There are 5 rooms in a house.Each room has 100W bulb and a 40W tubelight.If every day the bulb is use for 1hour and tubelight is use for 5hours in each room,then what will the cost of total electric energy consumed in 30days when one unit costs Rs.2.5

A shell of mass 0.02kg is fired by a gun of mass 100 kg. The muzzle speed of the shell is 80 m s^{-1}.Find the recoil speed of the gun.

Question 11The bluish colour of water in deep sea is due to(a) the presence of algae and other plants found in water(b) reflection of sky in water(c) scattering of light(d) absorption of light by the sea

Escape velocity of a body of 1 kg mass on a planet is 100 m/sec. Gravitational Potential energy of the body at the Planet is

2 conductors a and b have lengths in ratio 4:3and area of cross section ratio 1:2and resistivities in ratio 2:3 what will be the ratio of the resistance s

List four advantages of conserving water.

A 400 V, 50 Hz, 35 hp, 3-ϕ induction motor is drawing 50 A current at 0.8 power factor lagging. The rotor and stator copper losses are 950 W and 1.5 kW respectively. The friction and windage losses are 1 kW and core losses are 1.2 kW. The value of air gap power is ________ kW.25

146.Two cells when connected in series are balanced on 6m on a potentiometer.if the polarity of one of these cell is reversed,they balance,on 2m. The ratio of e.m.f of the two cells is?

What is meant by amplitude

For total internal reflection to take place, the angle of incidence i and the refractive index (μ) of the medium must satisfy the inequality

Which of the following options describes the etymology of word “biomass” correctly?

Find the radius of gyration of a uniform disc of mass m and radius R about an axis passing tangentially to the disc.

If mass and radius of the Earth are 6.0×1024 kg and 6.4×106 m respectively, calculate the force exerted by the Earth on a body of mass 1 kg.

The switching circuit given in the figure can be expressed in binary logic notation as,

A 50 kVA, 22 kV/220 V, Δ−Y distribution transformer has a resistance of 1 percent and reactance of 8 percentage.The magnitude of transformer's phase impedance referred to hv side will be ____

Question 11A successful forest conservation strategy should involve(a) protection of animals at the highest trophic level(b) protection of only consumers(c) protection of only herbivores(d) comprehensive programme to protect all the physical and biological components

The temperature of a thin wire of lead of length 5 cm is raised by 150 ∘C which increases its length by about 0.2 mm. What is the coefficient of cubical expansion of lead?

A container has N molecules at absolute temperature T . If the number of molecules is doubled but kinetic energy in the box remain same the absolute temperature of gas is