50278 + Interview Questions in Physics

1.	A closed cubical box is completely filled with water and is accelerated horizontally towards right with constant acceleration a. The resultant normal force by the water on the top of the box.
Answer» A closed cubical box is completely filled with water and is accelerated horizontally towards right with constant acceleration a. The resultant normal force by the water on the top of the box.

Discussion

2.	Space between plates is filled by two dielectrics K1 & K2, 23rd part is filled by K1 & 13rd is filled by K2, find effective dielectric constant. Area of the plates is A.
Answer» Space between plates is filled by two dielectrics $K_{1} & K_{2}, {\frac{2}{3}}^{r d}$ part is filled by $K_{1} & {\frac{1}{3}}^{r d}$ is filled by $K_{2}$ , find effective dielectric constant. Area of the plates is $A$ .

Discussion

3.	A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?
Answer» A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?

Discussion

4.	Car covers distance s with a speed vo. It further covers 3s distance with speed 2vo, and then next 5s distance with 3vo. Find its average speed.
Answer» Car covers distance $s$ with a speed $v_{o}$ . It further covers $3 s$ distance with speed $2 v_{o}$ , and then next $5 s$ distance with $3 v_{o}$ . Find its average speed.

Discussion

5.	The load versus elongation graph for four wires of the same material is shown in the figure. The thickest wire is represented by the line
Answer» The load versus elongation graph for four wires of the same material is shown in the figure. The thickest wire is represented by the line

Discussion

6.	A small bubble rises from the bottom of a lake, where the temperature and the pressure are 8 ∘C and 6.0 atm respectively, to the water's surface, where the temperature is 25 ∘C and the pressure is 1.0 atm. Calculate the final volume of the bubble if its initial volume was 2 mL.
Answer» A small bubble rises from the bottom of a lake, where the temperature and the pressure are $8^{\circ} C$ and $6.0 a t m$ respectively, to the water's surface, where the temperature is $25^{\circ} C$ and the pressure is $1.0 a t m$ . Calculate the final volume of the bubble if its initial volume was $2 m L$ .

Discussion

7.	Find the acceleration of the two bodies if the system is shown, is initially at rest. Take g=10 m/s2.
Answer» Find the acceleration of the two bodies if the system is shown, is initially at rest. Take $g = 10 {m/s}^{2}$ .

Discussion

8.	Two identical conducting spheres of a small radius are charged and placed 25 cm apart. It is observed that they attract each other with a force 1.728 N. The spheres are now connected by a thin conducting wire and the wire is then removed. It is observed that the spheres now repel each other with a force 0.576 N. Find the initial charges on the sphere.
Answer» Two identical conducting spheres of a small radius are charged and placed 25 cm apart. It is observed that they attract each other with a force 1.728 N. The spheres are now connected by a thin conducting wire and the wire is then removed. It is observed that the spheres now repel each other with a force 0.576 N. Find the initial charges on the sphere.

Discussion

9.	A glass prism is able to produce a spectrum when white light passes through it but a glass slab can't. Why?
Answer» A glass prism is able to produce a spectrum when white light passes through it but a glass slab can't. Why?

Discussion

10.	A narrow monochromatic beam of light of intensity I is incident on a glass plate as shown in figure. Another identical glass plate is kept close to the first one and parallel to it. Each glass plate reflects 25% of the light incident on it and transmits the remaining. Find the ratio of minimum and maximum intensities in the interference pattern formed by two beams obtained after one reflection at each plate.
Answer» A narrow monochromatic beam of light of intensity I is incident on a glass plate as shown in figure. Another identical glass plate is kept close to the first one and parallel to it. Each glass plate reflects $25 %$ of the light incident on it and transmits the remaining. Find the ratio of minimum and maximum intensities in the interference pattern formed by two beams obtained after one reflection at each plate.

Discussion

11.	A block sliding down a rough 45° inclined plane has half the velocity it would have had ,the inclined plane been smooth .the coefficient of sliding friction between block and inclined plane is???
Answer» A block sliding down a rough 45° inclined plane has half the velocity it would have had ,the inclined plane been smooth .the coefficient of sliding friction between block and inclined plane is???

Discussion

12.	A particle is projected from a horizontal plane (x−z plane) such that its velocity vector at time t is given by →v=a^i+(b−ct)^j. Its range on the horizontal plane is given by
Answer» A particle is projected from a horizontal plane ( $x - z$ plane) such that its velocity vector at time $t$ is given by $\to v = a^i + (b - c t)^j$ . Its range on the horizontal plane is given by

Discussion

13.	A simple pendulum is oscillating without damping. When the displacement of the bob is less than maximum, its acceleration vector →a is correctly shown in which of the following options ?
Answer» A simple pendulum is oscillating without damping. When the displacement of the bob is less than maximum, its acceleration vector $\to a$ is correctly shown in which of the following options ?

Discussion

14.	Two rods P and Q have equal lengths. Their thermal conductivities are K1 and K2 and cross-sectional areas are A1 and A2. When the temperature at ends of each rod are T1 and T2 respectively, the rate of flow of heat through P and Q will be equal, if
Answer» Two rods $P$ and $Q$ have equal lengths. Their thermal conductivities are $K_{1}$ and $K_{2}$ and cross-sectional areas are $A_{1}$ and $A_{2}$ . When the temperature at ends of each rod are $T_{1}$ and $T_{2}$ respectively, the rate of flow of heat through $P$ and $Q$ will be equal, if

Discussion

15.	A uniform rod of mass 'm' and Length 'L' is rotated about its perpendicular bisector at an angular speed ω. Calculate its angular momentum about its Axis of rotation?
Answer» A uniform rod of mass 'm' and Length 'L' is rotated about its perpendicular bisector at an angular speed $ω$ . Calculate its angular momentum about its Axis of rotation?

Discussion

16.	An equal force of 100 N is applied upon two similar sharp nails at different angles as shown in figure ⇒ The ratio of P(I) : P(II) will be?
Answer» An equal force of 100 N is applied upon two similar sharp nails at different angles as shown in figure ⇒ The ratio of P(I) : P(II) will be?

16.

An equal force of 100 N is applied upon two similar sharp nails at different angles as shown in figure ⇒ The ratio of P(I) : P(II) will be?

Answer»

An equal force of 100 N is applied upon two similar sharp nails at different angles as shown in figure ⇒

The ratio of P(I) : P(II) will be?

Discussion

17.	A particle is moving eastward with a velocity of 5 m/s.In 10s, the velocity of the particle changes to 5m/s northward.The average acceleration in this time is: a) 1/√2 m/s² b) 1/√2 m/s² c) 1/2 m/s² d) Zero
Answer» A particle is moving eastward with a velocity of 5 m/s.In 10s, the velocity of the particle changes to 5m/s northward.The average acceleration in this time is: a) 1/√2 m/s² b) 1/√2 m/s² c) 1/2 m/s² d) Zero

17.

A particle is moving eastward with a velocity of 5 m/s.In 10s, the velocity of the particle changes to 5m/s northward.The average acceleration in this time is: a) 1/√2 m/s² b) 1/√2 m/s² c) 1/2 m/s² d) Zero

Answer»

A particle is moving eastward with a velocity of 5 m/s.In 10s, the velocity of the particle changes to 5m/s northward.The average acceleration in this time is:

a) 1/√2 m/s²

b) 1/√2 m/s²

c) 1/2 m/s²

d) Zero

Discussion

18.	A cabin (in a horizontal plane) rotates on a smooth horizontal table with a uniform angular speed ω in a circular path of radius R. A smooth groove AB of length L(<<R is made inside the cabin as shown in the figure. If a particle is released from A to reach B along the path AB, then find the time taken by the particle to reach the point B.
Answer» A cabin (in a horizontal plane) rotates on a smooth horizontal table with a uniform angular speed $ω$ in a circular path of radius $R$ . A smooth groove $A B$ of length $L (<< R$ is made inside the cabin as shown in the figure. If a particle is released from $A$ to reach $B$ along the path $A B$ , then find the time taken by the particle to reach the point $B$ .

18.

A cabin (in a horizontal plane) rotates on a smooth horizontal table with a uniform angular speed ω in a circular path of radius R. A smooth groove AB of length L(<<R is made inside the cabin as shown in the figure. If a particle is released from A to reach B along the path AB, then find the time taken by the particle to reach the point B.

Answer»

A cabin (in a horizontal plane) rotates on a smooth horizontal table with a uniform angular speed $ω$ in a circular path of radius $R$ . A smooth groove $A B$ of length $L (<< R$ is made inside the cabin as shown in the figure. If a particle is released from $A$ to reach $B$ along the path $A B$ , then find the time taken by the particle to reach the point $B$ .

Discussion

19.	The radius of Krypton, the home planet of the famous D.C comic super-hero Superman, is 12 times the radius of earth. If the capacitance of earth is C, the capacitance of Krypton will be .
Answer» The radius of Krypton, the home planet of the famous D.C comic super-hero Superman, is 12 times the radius of earth. If the capacitance of earth is C, the capacitance of Krypton will be .

Discussion

20.	What is the frictional force when at the time of you lifting a body above a rough surface {as the bonds at the interference are trying to pull the body the back and also they are trying to trying to push the ground up}?
Answer» What is the frictional force when at the time of you lifting a body above a rough surface {as the bonds at the interference are trying to pull the body the back and also they are trying to trying to push the ground up}?

Discussion

21.	A motor cyclist moving with a velocity of 72 km/hr on flat road takes a turn on the road at a point where the radius of curvature of the road is 20 m. The acceleration due to gravity is 10 m/s2. In order to avoid skidding, he must not bend with respect to the vertical plane by an angle greater than
Answer» A motor cyclist moving with a velocity of $72 km/hr$ on flat road takes a turn on the road at a point where the radius of curvature of the road is $20 m$ . The acceleration due to gravity is $10 {m/s}^{2}$ . In order to avoid skidding, he must not bend with respect to the vertical plane by an angle greater than

Discussion

22.	The coefficient of static friction between a block of mass m and an incline is μs = 0.3. What can be the maximum angle θ of the incline with the horizontal so that the block does not slip on the plane? (Also called angle of repose)
Answer» The coefficient of static friction between a block of mass m and an incline is $μ_{s}$ = 0.3. What can be the maximum angle θ of the incline with the horizontal so that the block does not slip on the plane? (Also called angle of repose)

Discussion

23.	A particle starts from rest. The a−x curve is shown in the figure for the motion of particle. The speed of the particle at x=5 m is
Answer» A particle starts from rest. The $a - x$ curve is shown in the figure for the motion of particle. The speed of the particle at $x = 5 m$ is

Discussion

24.	In the arrangement shown in figure, pulleys are fixed and the ends P and Q of an unstretchable string move downwards with a uniform speed u. Mass m moves upwards with a speed of
Answer» In the arrangement shown in figure, pulleys are fixed and the ends $P$ and $Q$ of an unstretchable string move downwards with a uniform speed $u$ . Mass $m$ moves upwards with a speed of

Discussion

25.	In the figure shown, natural length of the spring =2 m. Force constant k=200 N/m. find the reading of the spring balance if A is kept at rest and B is displaced of the right by 1 m. Take g=10 m/s2
Answer» In the figure shown, natural length of the spring $= 2 m$ . Force constant $k = 200 N/m$ . find the reading of the spring balance if $A$ is kept at rest and $B$ is displaced of the right by $1 m$ . Take $g = 10 m / s^{2}$

Discussion

26.	Before applying force on a conductor, is there a relaxation time?
Answer» Before applying force on a conductor, is there a relaxation time?

Discussion

27.	If the displacement of particle at any time t is given by s=ut+12at2 where u is initial velocity (constant) and a is acceleration (constant) then, velocity of particle at any time t will be
Answer» If the displacement of particle at any time $t$ is given by $s = u t + \frac{1}{2} a t^{2}$ where $u$ is initial velocity (constant) and $a$ is acceleration (constant) then, velocity of particle at any time $t$ will be

Discussion

28.	A monkey of mass 20 kg is holding a vertical rope. The rope will not break when a mass of 25 kg is suspended from it but will break if the mass exceeds 25 kg. What is the maximum acceleration with which the monkey can climb up along the rope? g=10m/s2)
Answer» A monkey of mass $20 kg$ is holding a vertical rope. The rope will not break when a mass of $25 kg$ is suspended from it but will break if the mass exceeds $25 kg$ . What is the maximum acceleration with which the monkey can climb up along the rope? $g = 10 {m/s}^{2})$

Discussion

29.	In an adiabatic process, 4 g of H2 gas expands and temperature changes from 47∘C to 27∘C. Find the magnitude of the work done by the gas on the surroundings.
Answer» In an adiabatic process, $4 g$ of $H_{2}$ gas expands and temperature changes from $47^{\circ} C$ to $27^{\circ} C$ . Find the magnitude of the work done by the gas on the surroundings.

Discussion

30.	A prism of refractive index and refractive angle A produces minimum deviation δm of a ray on one face at an angle of incidence 450. The values of A and δm are respectively
Answer» A prism of refractive index and refractive angle A produces minimum deviation δ_m of a ray on one face at an angle of incidence 45⁰. The values of A and δ_m are respectively

Discussion

31.	If magnitude of the electric Flux entering the closed surface is 5 Nm2 /C and leaving the surface is 3Nm2 /C then the magnitude of net electric charge inside the surface is?
Answer» If magnitude of the electric Flux entering the closed surface is 5 Nm2 /C and leaving the surface is 3Nm2 /C then the magnitude of net electric charge inside the surface is?

Discussion

32.	How can one find the regiin of space where electroni can be found by using Schrodinger wave equation?
Answer» How can one find the regiin of space where electroni can be found by using Schrodinger wave equation?

Discussion

33.	Define Latent heat of vaporization. [2 MARKS]
Answer» Define Latent heat of vaporization. [2 MARKS]

Discussion

34.	If a particle has velocity v(t)=t2−6t+8, the average speed in 5 sec is
Answer» If a particle has velocity $v (t) = t^{2} - 6 t + 8$ , the average speed in $5 sec$ is

Discussion

35.	Why tension changes in vertical circular motion?
Answer» Why tension changes in vertical circular motion?

Discussion

36.	A clock has its second hand 2.0 cm long.Find the average speed and modulus of average velocity of the second hand in 15s.
Answer» A clock has its second hand 2.0 cm long.Find the average speed and modulus of average velocity of the second hand in 15s.

Discussion

37.	A copper rod of length l is rotated about one end perpendicular to the magnetic field B with constant angular velocity ω. The induced e.m.f. between the two ends is
Answer» A copper rod of length l is rotated about one end perpendicular to the magnetic field B with constant angular velocity ω. The induced e.m.f. between the two ends is

Discussion

38.	An electron is moving in a circular orbit in a magnetic field 2 × 10-3 Wb/m², the time period of electron is
Answer» An electron is moving in a circular orbit in a magnetic field 2 × 10^-3 Wb/m², the time period of electron is

Discussion

39.	What is the total flux through a sphere due to + q and - q charge enclosed on it ?
Answer» What is the total flux through a sphere due to + q and - q charge enclosed on it ?

Discussion

40.	If 10^9 electrons move out of a body to another body emery second, how much time is required to get a total charge of 1C on the other body.
Answer» If 10^9 electrons move out of a body to another body emery second, how much time is required to get a total charge of 1C on the other body.

Discussion

41.	If a car at rest is accelerated uniformly to the speed of 144 km/h in 20 s, distance covered by the car in 20 s is
Answer» If a car at rest is accelerated uniformly to the speed of $144 km/h$ in $20 s$ , distance covered by the car in $20 s$ is

Discussion

42.	Four bodies P, Q, R and S are projected with equal velocities having angles of projection 15∘,30∘,45∘ and 60∘ with the horizontal respectively. The body having shortest range is
Answer» Four bodies P, Q, R and S are projected with equal velocities having angles of projection $15^{\circ}, 30^{\circ}, 45^{\circ} a n d 60^{\circ}$ with the horizontal respectively. The body having shortest range is

Discussion

43.	The temperatures of equal masses of three different liquids A,B and C are 12∘C,19∘C and 28∘C respectively. The temperature when A and B are mixed is 16∘C, when B and C are mixed is 23∘C. What is the temperature when A and C are mixed?
Answer» The temperatures of equal masses of three different liquids $A, B$ and $C$ are $12^{\circ} C, 19^{\circ} C$ and $28^{\circ} C$ respectively. The temperature when $A$ and $B$ are mixed is $16^{\circ} C$ , when $B$ and $C$ are mixed is $23^{\circ} C$ . What is the temperature when $A$ and $C$ are mixed?

Discussion

44.	A cube with a mass m= 20g floats on the surface of water. Each face of the cube is 3cm long. what is the distance between lower surface of the cube and surface of the water? (Surface tension of water = 70 × 103 N/m , and angle of contact is acute)
Answer» A cube with a mass m= 20g floats on the surface of water. Each face of the cube is 3cm long. what is the distance between lower surface of the cube and surface of the water? (Surface tension of water = 70 $\times$ $10^{3}$ N/m , and angle of contact is acute)

Discussion

45.	A doubly ionized Lithium atom is like a hydrogen atom with atomic number 3. What is the wavelength of the radiation required to excite the electron from first to third Bohr's orbit?
Answer» A doubly ionized Lithium atom is like a hydrogen atom with atomic number 3. What is the wavelength of the radiation required to excite the electron from first to third Bohr's orbit?

Discussion

46.	A car moving with a speed of 50 km/hr, can be stopped by applying brakes after at least 6 m. If the same car is moving at a speed of 100 km/hr, the minimum stopping distance is
Answer» A car moving with a speed of $50 km/hr$ , can be stopped by applying brakes after at least $6 m$ . If the same car is moving at a speed of $100 km/hr$ , the minimum stopping distance is

Discussion

47.	A stone is projected from the ground with velocity 50 ms−1 and angle of 30∘. It crosses a wall after 3 s. How far beyond the wall the stone will strike the ground? Take g=10 ms−2
Answer» A stone is projected from the ground with velocity $50 m s^{- 1}$ and angle of $30^{\circ}$ . It crosses a wall after $3 s$ . How far beyond the wall the stone will strike the ground? Take $g = 10 m s^{- 2}$

Discussion

48.	A transverse wave of amplitude 0.50 mm and frequency 100 Hz is produced on a wire stretched to a tension of 100 N. If the wave speed is 100 ms−1, what average power is the source transmitting to the wire ?
Answer» A transverse wave of amplitude 0.50 mm and frequency 100 Hz is produced on a wire stretched to a tension of 100 N. If the wave speed is $100 m s^{- 1}$ , what average power is the source transmitting to the wire ?

Discussion

49.	A force F is applied to a block of mass 4√3 kg as shown in the diagram. What should be the maximum value of force so that the block does not move? (Take g=10 m/s2)
Answer» A force $F$ is applied to a block of mass $4 \sqrt{3} kg$ as shown in the diagram. What should be the maximum value of force so that the block does not move? (Take $g = 10 {m/s}^{2}$ )

Discussion

50.	A body of mass m is taken to the bottom of a deep mine. Then
Answer» A body of mass m is taken to the bottom of a deep mine. Then

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A closed cubical box is completely filled with water and is accelerated horizontally towards right with constant acceleration a. The resultant normal force by the water on the top of the box.

Space between plates is filled by two dielectrics K1 &amp; K2, 23rd part is filled by K1 &amp; 13rd is filled by K2, find effective dielectric constant. Area of the plates is A.

A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?

Car covers distance s with a speed vo. It further covers 3s distance with speed 2vo, and then next 5s distance with 3vo. Find its average speed.

The load versus elongation graph for four wires of the same material is shown in the figure. The thickest wire is represented by the line

A small bubble rises from the bottom of a lake, where the temperature and the pressure are 8 ∘C and 6.0 atm respectively, to the water's surface, where the temperature is 25 ∘C and the pressure is 1.0 atm. Calculate the final volume of the bubble if its initial volume was 2 mL.

Find the acceleration of the two bodies if the system is shown, is initially at rest. Take g=10 m/s2.

A glass prism is able to produce a spectrum when white light passes through it but a glass slab can't. Why?

A block sliding down a rough 45° inclined plane has half the velocity it would have had ,the inclined plane been smooth .the coefficient of sliding friction between block and inclined plane is???

A particle is projected from a horizontal plane (x−z plane) such that its velocity vector at time t is given by →v=a^i+(b−ct)^j. Its range on the horizontal plane is given by

A simple pendulum is oscillating without damping. When the displacement of the bob is less than maximum, its acceleration vector →a is correctly shown in which of the following options ?

Two rods P and Q have equal lengths. Their thermal conductivities are K1 and K2 and cross-sectional areas are A1 and A2. When the temperature at ends of each rod are T1 and T2 respectively, the rate of flow of heat through P and Q will be equal, if

A uniform rod of mass 'm' and Length 'L' is rotated about its perpendicular bisector at an angular speed ω. Calculate its angular momentum about its Axis of rotation?

An equal force of 100 N is applied upon two similar sharp nails at different angles as shown in figure ⇒ The ratio of P(I) : P(II) will be?

A particle is moving eastward with a velocity of 5 m/s.In 10s, the velocity of the particle changes to 5m/s northward.The average acceleration in this time is: a) 1/√2 m/s² b) 1/√2 m/s² c) 1/2 m/s² d) Zero

The radius of Krypton, the home planet of the famous D.C comic super-hero Superman, is 12 times the radius of earth. If the capacitance of earth is C, the capacitance of Krypton will be .

What is the frictional force when at the time of you lifting a body above a rough surface {as the bonds at the interference are trying to pull the body the back and also they are trying to trying to push the ground up}?

A motor cyclist moving with a velocity of 72 km/hr on flat road takes a turn on the road at a point where the radius of curvature of the road is 20 m. The acceleration due to gravity is 10 m/s2. In order to avoid skidding, he must not bend with respect to the vertical plane by an angle greater than

The coefficient of static friction between a block of mass m and an incline is μs = 0.3. What can be the maximum angle θ of the incline with the horizontal so that the block does not slip on the plane? (Also called angle of repose)

A particle starts from rest. The a−x curve is shown in the figure for the motion of particle. The speed of the particle at x=5 m is

In the arrangement shown in figure, pulleys are fixed and the ends P and Q of an unstretchable string move downwards with a uniform speed u. Mass m moves upwards with a speed of

In the figure shown, natural length of the spring =2 m. Force constant k=200 N/m. find the reading of the spring balance if A is kept at rest and B is displaced of the right by 1 m. Take g=10 m/s2

Before applying force on a conductor, is there a relaxation time?

If the displacement of particle at any time t is given by s=ut+12at2 where u is initial velocity (constant) and a is acceleration (constant) then, velocity of particle at any time t will be

A monkey of mass 20 kg is holding a vertical rope. The rope will not break when a mass of 25 kg is suspended from it but will break if the mass exceeds 25 kg. What is the maximum acceleration with which the monkey can climb up along the rope? g=10m/s2)

In an adiabatic process, 4 g of H2 gas expands and temperature changes from 47∘C to 27∘C. Find the magnitude of the work done by the gas on the surroundings.

A prism of refractive index and refractive angle A produces minimum deviation δm of a ray on one face at an angle of incidence 450. The values of A and δm are respectively

If magnitude of the electric Flux entering the closed surface is 5 Nm2 /C and leaving the surface is 3Nm2 /C then the magnitude of net electric charge inside the surface is?

How can one find the regiin of space where electroni can be found by using Schrodinger wave equation?

Define Latent heat of vaporization. [2 MARKS]

If a particle has velocity v(t)=t2−6t+8, the average speed in 5 sec is

Why tension changes in vertical circular motion?

A clock has its second hand 2.0 cm long.Find the average speed and modulus of average velocity of the second hand in 15s.

A copper rod of length l is rotated about one end perpendicular to the magnetic field B with constant angular velocity ω. The induced e.m.f. between the two ends is

An electron is moving in a circular orbit in a magnetic field 2 × 10-3 Wb/m², the time period of electron is

What is the total flux through a sphere due to + q and - q charge enclosed on it ?

If 10^9 electrons move out of a body to another body emery second, how much time is required to get a total charge of 1C on the other body.

If a car at rest is accelerated uniformly to the speed of 144 km/h in 20 s, distance covered by the car in 20 s is

Four bodies P, Q, R and S are projected with equal velocities having angles of projection 15∘,30∘,45∘ and 60∘ with the horizontal respectively. The body having shortest range is

The temperatures of equal masses of three different liquids A,B and C are 12∘C,19∘C and 28∘C respectively. The temperature when A and B are mixed is 16∘C, when B and C are mixed is 23∘C. What is the temperature when A and C are mixed?

A cube with a mass m= 20g floats on the surface of water. Each face of the cube is 3cm long. what is the distance between lower surface of the cube and surface of the water? (Surface tension of water = 70 × 103 N/m , and angle of contact is acute)

A doubly ionized Lithium atom is like a hydrogen atom with atomic number 3. What is the wavelength of the radiation required to excite the electron from first to third Bohr's orbit?

A car moving with a speed of 50 km/hr, can be stopped by applying brakes after at least 6 m. If the same car is moving at a speed of 100 km/hr, the minimum stopping distance is

A stone is projected from the ground with velocity 50 ms−1 and angle of 30∘. It crosses a wall after 3 s. How far beyond the wall the stone will strike the ground? Take g=10 ms−2

A transverse wave of amplitude 0.50 mm and frequency 100 Hz is produced on a wire stretched to a tension of 100 N. If the wave speed is 100 ms−1, what average power is the source transmitting to the wire ?

A force F is applied to a block of mass 4√3 kg as shown in the diagram. What should be the maximum value of force so that the block does not move? (Take g=10 m/s2)

A body of mass m is taken to the bottom of a deep mine. Then

Space between plates is filled by two dielectrics K1 & K2, 23rd part is filled by K1 & 13rd is filled by K2, find effective dielectric constant. Area of the plates is A.