50278 + Interview Questions in Physics

1.	When equal volumes of the following solutions are mixed, the precipitation of AgCl (Ksp=1.8×10−10) will occur with:
Answer» When equal volumes of the following solutions are mixed, the precipitation of $A g C l (K_{s p} = 1.8 \times 10^{- 10})$ will occur with:

Discussion

2.	A black body at 200 K is found to exit maximum energy at a wavelength of 14 μ m. When its temperature is raised to 1000K, the wavelength at which maximum energy is emitted is
Answer» A black body at 200 K is found to exit maximum energy at a wavelength of 14 $μ$ m. When its temperature is raised to 1000K, the wavelength at which maximum energy is emitted is

Discussion

3.	A particle having mass 10g oscillates according to the equation x=(2.0cm) sin[(100s−1)t+π6]. Find the spring constant
Answer» A particle having mass 10g oscillates according to the equation $x = (2.0 c m) s i n [(100 s^{- 1}) t + \frac{π}{6}]$ . Find the spring constant

Discussion

4.	Figure shows a loop – the – loop track of radius R. A car (without engine) starts from a platform at a distance h above the top of the loop and goes around the loop without falling off the track. Then the minimum value of h for a successful looping is (neglect friction).
Answer» Figure shows a loop – the – loop track of radius $R$ . A car (without engine) starts from a platform at a distance $h$ above the top of the loop and goes around the loop without falling off the track. Then the minimum value of $h$ for a successful looping is (neglect friction).

Discussion

5.	From the top of a 19.6 m high tower, a ball is thrown horizontally. If the line joining the point of projection to the point where it hits the ground, makes an angle of 45∘ with the horizontal, then the initial velocity of the ball is
Answer» From the top of a $19.6 m$ high tower, a ball is thrown horizontally. If the line joining the point of projection to the point where it hits the ground, makes an angle of $45^{\circ}$ with the horizontal, then the initial velocity of the ball is

Discussion

6.	The closed container filled with water is moving with some acceleration as shown in the figure. Then PA−PD is :-
Answer» The closed container filled with water is moving with some acceleration as shown in the figure. Then $P_{A} - P_{D}$ is :-

Discussion

7.	Compare the speed of the three particles A,B and C as per the distance-time graph shown below.
Answer» Compare the speed of the three particles $A, B$ and $C$ as per the distance-time graph shown below.

Discussion

8.	The correct set of four quantum numbers for the valence electron of cesium (z = 55) is:
Answer» The correct set of four quantum numbers for the valence electron of cesium (z = 55) is:

Discussion

9.	Two identical spheres each of mass 1.20 kg and radius 10.0 cm are fixed at the ends of a light rod so that the separation between the centres is 50.0 cm. Find the moment of intertia of the system about an axis perpendicular to the rod passing through its middle point.
Answer» Two identical spheres each of mass 1.20 kg and radius 10.0 cm are fixed at the ends of a light rod so that the separation between the centres is 50.0 cm. Find the moment of intertia of the system about an axis perpendicular to the rod passing through its middle point.

Discussion

10.	What is a spin of an elementary particle?
Answer» What is a spin of an elementary particle?

Discussion

11.	A projectile is thrown with a velocity of 10√2 m/s at an angle of 45∘ with horizontal. The interval between the moments when speed is √125 m/s is (g=10 m/s2)
Answer» A projectile is thrown with a velocity of $10 \sqrt{2} m / s$ at an angle of $45^{\circ}$ with horizontal. The interval between the moments when speed is $\sqrt{125} m / s$ is $(g = 10 m / s^{2})$

Discussion

12.	A ball is rolled off the edge of a horizontal table at a speed of 4 m/second. It hits the ground after 0.4 second. Which statement given below is true
Answer» A ball is rolled off the edge of a horizontal table at a speed of 4 m/second. It hits the ground after 0.4 second. Which statement given below is true

Discussion

13.	The magnetic field at the centre of the circular coil carrying current of 4A is
Answer» The magnetic field at the centre of the circular coil carrying current of 4A is

Discussion

14.	A glass capillary tube of internal radius r=0.25 mm is immersed in water. The top end of the tube projects by 2 cm above the surface of water. At what angle does the liquid meet the ends of the tube? [surface tension of water = 0.07 N m−1]
Answer» A glass capillary tube of internal radius $r = 0.25 mm$ is immersed in water. The top end of the tube projects by $2 cm$ above the surface of water. At what angle does the liquid meet the ends of the tube? [surface tension of water = $0.07 N m^{- 1}$ ]

Discussion

15.	A block of mass m is placed at the bottom of a massless smooth wedge which is placed on a horizontal surface. When we push the wedge with a constant force, the block moves up the wedge. The work done by the external agent when the block has a speed v and has reached the top of the wedge is
Answer» A block of mass $m$ is placed at the bottom of a massless smooth wedge which is placed on a horizontal surface. When we push the wedge with a constant force, the block moves up the wedge. The work done by the external agent when the block has a speed $v$ and has reached the top of the wedge is

Discussion

16.	A near UV photon of 300 nm is absorbed by a gas and then re-emitted as 2 photons. One photon is red with wavelength 760 nm. Hence wavelength of the second photon is:
Answer» A near UV photon of 300 nm is absorbed by a gas and then re-emitted as 2 photons. One photon is red with wavelength 760 nm. Hence wavelength of the second photon is:

Discussion

17.	A particle moves in a circular path with a uniform speed. Its motion is
Answer» A particle moves in a circular path with a uniform speed. Its motion is

Discussion

18.	Prove that Vab vector=Va vector-Vb vector
Answer» Prove that Vab vector=Va vector-Vb vector

Discussion

19.	A gas at 27∘C has a volume V and pressure P. On heating its pressure is doubled and volume becomes three times. The resulting temperature of the gas will be
Answer» A gas at $27^{\circ} C$ has a volume V and pressure P. On heating its pressure is doubled and volume becomes three times. The resulting temperature of the gas will be

Discussion

20.	A particle travels in a circle of radius 20 cm at a speed that uniformly increases. If the speed changes form 5.0 ms to 6.0 ms in 2.0 s, find the angular acceleration.
Answer» A particle travels in a circle of radius 20 $c m$ at a speed that uniformly increases. If the speed changes form 5.0 $\frac{m}{s}$ to 6.0 $\frac{m}{s}$ in 2.0 $s$ , find the angular acceleration.

Discussion

21.	An object starts from A and moves to B with a velocity of 40 m/s. Then it returns back to A with a velocity of 60 m/s. Find the displacement of the object.
Answer» An object starts from A and moves to B with a velocity of 40 m/s. Then it returns back to A with a velocity of 60 m/s. Find the displacement of the object.

Discussion

22.	A block of mass 10 kg is placed on rough horizontal surface whose coefficient of friction is 0.5. If a horizontal force of 100 N is applied on it, then acceleration of block will be [Take g=10 ms−2]
Answer» A block of mass $10 kg$ is placed on rough horizontal surface whose coefficient of friction is $0.5$ . If a horizontal force of $100 N$ is applied on it, then acceleration of block will be [Take $g = 10 {ms}^{- 2}$ ]

Discussion

23.	A train starts from rest and moves with a constant acceleration of 2.0 m/s2 for half a minute. The brakes are then applied and the train comes to rest in one minute. Find (a) the total distance moved by the train, (b) the maximum speed attained by the train and (c) the position(s) of the train at half the maximum speed.
Answer» A train starts from rest and moves with a constant acceleration of 2.0 m/s2 for half a minute. The brakes are then applied and the train comes to rest in one minute. Find (a) the total distance moved by the train, (b) the maximum speed attained by the train and (c) the position(s) of the train at half the maximum speed.

Discussion

24.	A quantity of air is taken from state a to state b along a path that is a straight line in the P-V diagram.In this process, what happens to the temperature of the gas?
Answer» A quantity of air is taken from state a to state b along a path that is a straight line in the P-V diagram.In this process, what happens to the temperature of the gas?

24.

A quantity of air is taken from state a to state b along a path that is a straight line in the P-V diagram.In this process, what happens to the temperature of the gas?

Answer»

A quantity of air is taken from state a to state b along a path that is a straight line in the P-V diagram.In this process, what happens to the temperature of the gas?

Discussion

25.	Vectors →A and →B makes angle of 20∘ and 110∘ respectively with +x-axis. The magnitude of these vectors are 5 m and 12 m respectively. Then the magnitude of the resultant vector is
Answer» Vectors $\to A$ and $\to B$ makes angle of $20^{\circ}$ and $110^{\circ}$ respectively with $+ x$ -axis. The magnitude of these vectors are $5 m$ and $12 m$ respectively. Then the magnitude of the resultant vector is

Discussion

26.	A body of mass 2 kg is sliding on an inclined plane as shown Mass of the wedge is 4 kg. Find the velocity of the wedge just before the body reaches the ground.
Answer» A body of mass $2 kg$ is sliding on an inclined plane as shown Mass of the wedge is $4 kg$ . Find the velocity of the wedge just before the body reaches the ground.

Discussion

27.	Two condensers C1 and C2 in a circuit are joined as shown in the figure The potential of point A is V1 and that of B is V2. The potential of point D will be
Answer» Two condensers C₁ and C₂ in a circuit are joined as shown in the figure The potential of point A is V₁ and that of B is V₂. The potential of point D will be

Discussion

28.	Two different metal rods of equal lengths and equal areas of cross-section have their ends kept at the same temperatures θ1 and θ1 If k1 and k2 are their thermal conductivities, ρ1 and ρ2 their densities and s1 and s2 their specific heats, then the rate of flow of heat in the two rods will be the same if
Answer» Two different metal rods of equal lengths and equal areas of cross-section have their ends kept at the same temperatures $θ_{1}$ and $θ_{1}$ If $k_{1}$ and $k_{2}$ are their thermal conductivities, $ρ_{1}$ and $ρ_{2}$ their densities and $s_{1}$ and $s_{2}$ their specific heats, then the rate of flow of heat in the two rods will be the same if

Discussion

29.	A force of magnitude 18 N acts on a particle in the direction of a vector →A=2^i−4^j+4^k, which results in the change of position of the particle from (3,3,5) m to (2,−1,4) m. The work done by the force is (in Joule )
Answer» A force of magnitude $18 N$ acts on a particle in the direction of a vector $\to A = 2^i - 4^j + 4^k$ , which results in the change of position of the particle from $(3, 3, 5) m$ to $(2, - 1, 4) m$ . The work done by the force is (in Joule )

Discussion

30.	A totally reflecting small plane mirror placed horizontally faces a parallel beam of light as shown in figure. The mass of the mirror is 20 g. Assume that there is no absorption in the lens and that 30% of the light emitted by the source goes through the lens. The power of the source needed to support the weight of the mirror (in MW) is (Take g = 10 m/s2)
Answer» A totally reflecting small plane mirror placed horizontally faces a parallel beam of light as shown in figure. The mass of the mirror is $20 g$ . Assume that there is no absorption in the lens and that 30% of the light emitted by the source goes through the lens. The power of the source needed to support the weight of the mirror (in MW) is (Take g = 10 $m / s^{2}$ )

Discussion

31.	A gaseous mixture enclosed in a vessel of volume ′V′ consists of 2 gram mole of gas A and 4 gram mole of gas B at a certain temperature T. The gram molecular weights of the gases A and B are 4 and 16 respectively. The molecular weight of the mixture will be
Answer» A gaseous mixture enclosed in a vessel of volume $^{'} V^{'}$ consists of $2$ gram mole of gas $A$ and $4$ gram mole of gas $B$ at a certain temperature $T$ . The gram molecular weights of the gases $A$ and $B$ are $4$ and $16$ respectively. The molecular weight of the mixture will be

Discussion

32.	A body is projected with u =19.6m/s find the max height and time of flight
Answer» A body is projected with u =19.6m/s find the max height and time of flight

Discussion

33.	A force F acts between sodium and chlorine ions of salt (sodium chloride), when ions are 1 cm apart in air. The permittivity of air and dielectric constant of water are ε0 and K respectively. When a piece of salt is placed in water, electrical force acting between sodium and chlorine ions 1 cm apart is
Answer» A force $F$ acts between sodium and chlorine ions of salt (sodium chloride), when ions are $1 c m$ apart in air. The permittivity of air and dielectric constant of water are $ε_{0}$ and $K$ respectively. When a piece of salt is placed in water, electrical force acting between sodium and chlorine ions $1 c m$ apart is

Discussion

34.	Dimensional representation of co-efficient of friction is
Answer» Dimensional representation of co-efficient of friction is

Discussion

35.	Eight small drops, each of radius r and having same charge q are combined to form a big drop. The ratio of potential of the bigger drop to the smaller drop is
Answer» Eight small drops, each of radius $r$ and having same charge $q$ are combined to form a big drop. The ratio of potential of the bigger drop to the smaller drop is

Discussion

36.	A lift is moving down with an acceleration a. A man in the lift drops a ball inside the lift. The acceleration of the ball as observed by the man in the lift and a man standing stationary on the ground respectively are :
Answer» A lift is moving down with an acceleration a. A man in the lift drops a ball inside the lift. The acceleration of the ball as observed by the man in the lift and a man standing stationary on the ground respectively are :

Discussion

37.	When u238 nucleus, originally at rest, decays by emitting an alpha particle having a speed u, the recoil speed of the residual nucleus is
Answer» When $u^{238}$ nucleus, originally at rest, decays by emitting an alpha particle having a speed u, the recoil speed of the residual nucleus is

Discussion

38.	In the below figure, a square loop consisting of an inductor of inductance L and resistor of resistance R is placed between two long parallel wires. The two long straight wires have time-varying current of magnitude I=I0 cos ωt A, but the directions of current in them are opposite.Magnitude of emf in this circuit only due to flux change associated with two long straight current carrying wires will be
Answer» In the below figure, a square loop consisting of an inductor of inductance L and resistor of resistance R is placed between two long parallel wires. The two long straight wires have time-varying current of magnitude $I = I_{0} c o s ω t$ $A$ , but the directions of current in them are opposite.Magnitude of emf in this circuit only due to flux change associated with two long straight current carrying wires will be

Discussion

39.	What is radioactive time-scale
Answer» What is radioactive time-scale

Discussion

40.	A particle is projected from the ground with a kinetic energy E at an angle of 60• with the horizontal. It's kinetic energy at the highest point of its motion will be
Answer» A particle is projected from the ground with a kinetic energy E at an angle of 60• with the horizontal. It's kinetic energy at the highest point of its motion will be

Discussion

41.	When water droplets merge to form a bigger drop?
Answer» When water droplets merge to form a bigger drop?

Discussion

42.	Focal length of a thin convex lens is 30 cm. At a distance of 10 cm from the lens, there is a plane refracting surface of refractive index 32. A parallel beam of monochromatic light rays incident on the lens, then they converge at a distance of
Answer» Focal length of a thin convex lens is 30 cm. At a distance of 10 cm from the lens, there is a plane refracting surface of refractive index $\frac{3}{2}$ . A parallel beam of monochromatic light rays incident on the lens, then they converge at a distance of

Discussion

43.	The input characteristics of a transistor in CE mode is the graph obtained by plotting
Answer» The input characteristics of a transistor in CE mode is the graph obtained by plotting

Discussion

44.	For the given situation, which of the following options correctly represents the equation for SHM?
Answer» For the given situation, which of the following options correctly represents the equation for SHM?

Discussion

45.	Which of the following curve correctly represents impedance(Z) with frequency (n) of applied voltage
Answer» Which of the following curve correctly represents impedance(Z) with frequency (n) of applied voltage

Discussion

46.	A 50 kg motor rests on four cylindrical rubber blocks. Each block has a height of 4 cm and a cross-sectional area of 16 cm2. The shear modulus of rubber is 2×106N/m2. A sideways force of 500 N is applied to the motor. The distance that the motor moves sideways (in cm) is:
Answer» A $50 k g$ motor rests on four cylindrical rubber blocks. Each block has a height of $4 c m$ and a cross-sectional area of $16 c m^{2}$ . The shear modulus of rubber is $2 \times 10^{6} N / m^{2}$ . A sideways force of $500 N$ is applied to the motor. The distance that the motor moves sideways (in $c m$ ) is:

Discussion

47.	An ideal gas is taken through a cyclic thermodynamic process through four steps. The amounts of heat involved in these steps are Q1=5960 J,Q=−5585 J,Q3=−2980 J and Q4=3645 J respectively. The corresponding quantities of work done by gas for each steps are W1=2200 J, W2=−825 J, W3=−1100 J and W4=765 J respectively. The efficiency of the cycle is
Answer» An ideal gas is taken through a cyclic thermodynamic process through four steps. The amounts of heat involved in these steps are $Q_{1} = 5960 J, Q = - 5585 J, Q_{3} = - 2980 J$ and $Q_{4} = 3645 J$ respectively. The corresponding quantities of work done by gas for each steps are $W_{1} = 2200 J, W_{2} = - 825 J, W_{3} = - 1100 J$ and $W_{4} = 765 J$ respectively. The efficiency of the cycle is

Discussion

48.	If kinetic energy of a body is given as k=Cx where C is constant and x is distance from origin then, dimensional formula for C is
Answer» If kinetic energy of a body is given as $k = C x$ where $C$ is constant and $x$ is distance from origin then, dimensional formula for $C$ is

Discussion

49.	A cube of ice floats partly in water and partly in kerosene oil. Specific gravity of kerosene oil and that of ice is 0.8 and 0.9 respectively. Ratio of the volume of ice immersed in water to that in kerosene oil is
Answer» A cube of ice floats partly in water and partly in kerosene oil. Specific gravity of kerosene oil and that of ice is $0.8$ and $0.9$ respectively. Ratio of the volume of ice immersed in water to that in kerosene oil is

Discussion

50.	A stone of mass 5 kg falls from the top of a cliff having height 50 m and buries 1 m in sand find average resistive force offered by sand and time takes to penetrate.
Answer» A stone of mass 5 kg falls from the top of a cliff having height 50 m and buries 1 m in sand find average resistive force offered by sand and time takes to penetrate.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

When equal volumes of the following solutions are mixed, the precipitation of AgCl (Ksp=1.8×10−10) will occur with:

A black body at 200 K is found to exit maximum energy at a wavelength of 14 μ m. When its temperature is raised to 1000K, the wavelength at which maximum energy is emitted is

A particle having mass 10g oscillates according to the equation x=(2.0cm) sin[(100s−1)t+π6]. Find the spring constant

Figure shows a loop – the – loop track of radius R. A car (without engine) starts from a platform at a distance h above the top of the loop and goes around the loop without falling off the track. Then the minimum value of h for a successful looping is (neglect friction).

From the top of a 19.6 m high tower, a ball is thrown horizontally. If the line joining the point of projection to the point where it hits the ground, makes an angle of 45∘ with the horizontal, then the initial velocity of the ball is

The closed container filled with water is moving with some acceleration as shown in the figure. Then PA−PD is :-

Compare the speed of the three particles A,B and C as per the distance-time graph shown below.

The correct set of four quantum numbers for the valence electron of cesium (z = 55) is:

Two identical spheres each of mass 1.20 kg and radius 10.0 cm are fixed at the ends of a light rod so that the separation between the centres is 50.0 cm. Find the moment of intertia of the system about an axis perpendicular to the rod passing through its middle point.

What is a spin of an elementary particle?

A projectile is thrown with a velocity of 10√2 m/s at an angle of 45∘ with horizontal. The interval between the moments when speed is √125 m/s is (g=10 m/s2)

A ball is rolled off the edge of a horizontal table at a speed of 4 m/second. It hits the ground after 0.4 second. Which statement given below is true

The magnetic field at the centre of the circular coil carrying current of 4A is

A glass capillary tube of internal radius r=0.25 mm is immersed in water. The top end of the tube projects by 2 cm above the surface of water. At what angle does the liquid meet the ends of the tube? [surface tension of water = 0.07 N m−1]

A block of mass m is placed at the bottom of a massless smooth wedge which is placed on a horizontal surface. When we push the wedge with a constant force, the block moves up the wedge. The work done by the external agent when the block has a speed v and has reached the top of the wedge is

A near UV photon of 300 nm is absorbed by a gas and then re-emitted as 2 photons. One photon is red with wavelength 760 nm. Hence wavelength of the second photon is:

A particle moves in a circular path with a uniform speed. Its motion is

Prove that Vab vector=Va vector-Vb vector

A gas at 27∘C has a volume V and pressure P. On heating its pressure is doubled and volume becomes three times. The resulting temperature of the gas will be

A particle travels in a circle of radius 20 cm at a speed that uniformly increases. If the speed changes form 5.0 ms to 6.0 ms in 2.0 s, find the angular acceleration.

An object starts from A and moves to B with a velocity of 40 m/s. Then it returns back to A with a velocity of 60 m/s. Find the displacement of the object.

A block of mass 10 kg is placed on rough horizontal surface whose coefficient of friction is 0.5. If a horizontal force of 100 N is applied on it, then acceleration of block will be [Take g=10 ms−2]

A quantity of air is taken from state a to state b along a path that is a straight line in the P-V diagram.In this process, what happens to the temperature of the gas?

Vectors →A and →B makes angle of 20∘ and 110∘ respectively with +x-axis. The magnitude of these vectors are 5 m and 12 m respectively. Then the magnitude of the resultant vector is

A body of mass 2 kg is sliding on an inclined plane as shown Mass of the wedge is 4 kg. Find the velocity of the wedge just before the body reaches the ground.

Two condensers C1 and C2 in a circuit are joined as shown in the figure The potential of point A is V1 and that of B is V2. The potential of point D will be

A force of magnitude 18 N acts on a particle in the direction of a vector →A=2^i−4^j+4^k, which results in the change of position of the particle from (3,3,5) m to (2,−1,4) m. The work done by the force is (in Joule )

A gaseous mixture enclosed in a vessel of volume ′V′ consists of 2 gram mole of gas A and 4 gram mole of gas B at a certain temperature T. The gram molecular weights of the gases A and B are 4 and 16 respectively. The molecular weight of the mixture will be

A body is projected with u =19.6m/s find the max height and time of flight

Dimensional representation of co-efficient of friction is

Eight small drops, each of radius r and having same charge q are combined to form a big drop. The ratio of potential of the bigger drop to the smaller drop is

A lift is moving down with an acceleration a. A man in the lift drops a ball inside the lift. The acceleration of the ball as observed by the man in the lift and a man standing stationary on the ground respectively are :

When u238 nucleus, originally at rest, decays by emitting an alpha particle having a speed u, the recoil speed of the residual nucleus is

What is radioactive time-scale

A particle is projected from the ground with a kinetic energy E at an angle of 60• with the horizontal. It's kinetic energy at the highest point of its motion will be

When water droplets merge to form a bigger drop?

Focal length of a thin convex lens is 30 cm. At a distance of 10 cm from the lens, there is a plane refracting surface of refractive index 32. A parallel beam of monochromatic light rays incident on the lens, then they converge at a distance of

The input characteristics of a transistor in CE mode is the graph obtained by plotting

For the given situation, which of the following options correctly represents the equation for SHM?

Which of the following curve correctly represents impedance(Z) with frequency (n) of applied voltage

A 50 kg motor rests on four cylindrical rubber blocks. Each block has a height of 4 cm and a cross-sectional area of 16 cm2. The shear modulus of rubber is 2×106N/m2. A sideways force of 500 N is applied to the motor. The distance that the motor moves sideways (in cm) is:

If kinetic energy of a body is given as k=Cx where C is constant and x is distance from origin then, dimensional formula for C is

A cube of ice floats partly in water and partly in kerosene oil. Specific gravity of kerosene oil and that of ice is 0.8 and 0.9 respectively. Ratio of the volume of ice immersed in water to that in kerosene oil is

A stone of mass 5 kg falls from the top of a cliff having height 50 m and buries 1 m in sand find average resistive force offered by sand and time takes to penetrate.