50278 + Interview Questions in Physics

1.	Four point masses, each of value m, are placed at the corners of a square ABCD of side l. The moment of inertia of this system about an axis passing through A and parallel to BD is
Answer» Four point masses, each of value $m$ , are placed at the corners of a square ABCD of side $l$ . The moment of inertia of this system about an axis passing through A and parallel to BD is

Discussion

2.	Neglecting the density of air, the terminal velocity obtained by a raindrop of radius 0.3 mm falling through the air of viscosity 1.8×10−5 Ns/m2 will be (ρwater=103kg/m3)
Answer» Neglecting the density of air, the terminal velocity obtained by a raindrop of radius 0.3 mm falling through the air of viscosity $1.8 \times 10^{- 5} N s / m^{2}$ will be $(ρ_{w a t e r} = 10^{3} k g / m^{3})$

Discussion

3.	The densities of two solid spheres A and B of the same radii R vary with radial distance r as ρA(r)=k(rR) and ρB(r)=k(rR)5, respectively, where k is a constant. The moments of inertia of the individual spheres about axes passing through their centres are IA and IB, respectively. If IBIA=n10, the value of n is
Answer» The densities of two solid spheres A and B of the same radii $R$ vary with radial distance r as $ρ_{A} (r) = k (\frac{r}{R})$ and $ρ_{B} (r) = k {(\frac{r}{R})}^{5}$ , respectively, where $k$ is a constant. The moments of inertia of the individual spheres about axes passing through their centres are $I_{A}$ and $I_{B}$ , respectively. If $\frac{I_{B}}{I_{A}} = \frac{n}{10}$ , the value of $n$ is

Discussion

4.	Distance between the centers of two stars is 10a. The masses of these stars are M and 16M and their radii a and 2a respectively. A body of mass m is fired straight from the surface of the larger star towards the smaller star. The minimum initial speed for the body to reach the surface of smaller star is
Answer» Distance between the centers of two stars is 10a. The masses of these stars are M and 16M and their radii a and 2a respectively. A body of mass m is fired straight from the surface of the larger star towards the smaller star. The minimum initial speed for the body to reach the surface of smaller star is

Discussion

5.	A plane-convex lens fits exactly into a plane-concave lens. Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive index μ1 and μ2 and R is the radius of curvature of the curved surface of the lenses, then the focal length of the combination is
Answer» A plane-convex lens fits exactly into a plane-concave lens. Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive index $μ_{1}$ and $μ_{2}$ and R is the radius of curvature of the curved surface of the lenses, then the focal length of the combination is

Discussion

6.	In the circuit shown the capacitor is initially charged with a 12 V battery, when switch S1 is open and switch S2 is closed. S1 is then closed and, at the same time, S2 is opened. The maximum value of current in the circuit is:
Answer» In the circuit shown the capacitor is initially charged with a 12 V battery, when switch $S_{1}$ is open and switch $S_{2}$ is closed. $S_{1}$ is then closed and, at the same time, $S_{2}$ is opened. The maximum value of current in the circuit is:

Discussion

7.	Write a relation for polarisation→P of a dielectric material in the presence of an external electric field →E
Answer» Write a relation for polarisation $\to P$ of a dielectric material in the presence of an external electric field $\to E$

Discussion

8.	Two inductor coils of self inductance 3H and 6H respectively are connected with a resistance 10Ω and a battery 10V as shown in figure. The ratio of total energy stored at steady state in the inductors to that of heat developed in resistance in 10 seconds at the steady state is (neglect mutual inductance between L1 and L2)
Answer» Two inductor coils of self inductance 3H and 6H respectively are connected with a resistance $10 Ω$ and a battery 10V as shown in figure. The ratio of total energy stored at steady state in the inductors to that of heat developed in resistance in 10 seconds at the steady state is (neglect mutual inductance between $L_{1}$ and $L_{2}$ )

8.

Two inductor coils of self inductance 3H and 6H respectively are connected with a resistance 10Ω and a battery 10V as shown in figure. The ratio of total energy stored at steady state in the inductors to that of heat developed in resistance in 10 seconds at the steady state is (neglect mutual inductance between L1 and L2)

Answer»

Two inductor coils of self inductance 3H and 6H respectively are connected with a resistance $10 Ω$ and a battery 10V as shown in figure. The ratio of total energy stored at steady state in the inductors to that of heat developed in resistance in 10 seconds at the steady state is (neglect mutual inductance between $L_{1}$ and $L_{2}$ )

Discussion

9.	A body of mass 600 gm is attached to a spring of spring constant k=100 N/m and it is performing damped oscillations. If damping constant is 0.2 and driving force is F=F0cos(ωt) where F0=20 N, find the amplitude of oscillations at resonance.
Answer» A body of mass $600 gm$ is attached to a spring of spring constant $k = 100 N/m$ and it is performing damped oscillations. If damping constant is $0.2$ and driving force is $F = F_{0} cos (ω t)$ where $F_{0} = 20 N$ , find the amplitude of oscillations at resonance.

Discussion

10.	Three particles of same mass m are attached by massless rods of same length l and placed at the vertices of an equilateral triangle. The angular momentum about an axis XX′ will be nmωl24, where n is
Answer» Three particles of same mass $m$ are attached by massless rods of same length $l$ and placed at the vertices of an equilateral triangle. The angular momentum about an axis $X X^{'}$ will be $\frac{n m ω l^{2}}{4}$ , where $n$ is

Discussion

11.	A non uniform string of mass 45 kg and length 1.5 m has a variable linear mass density given by μ=Kx, where x is the distance from one end of the string and K is a constant. Tension in the string is 15 N (uniform). Find the time (in seconds) required for a pulse generated at one end of the string to travel to the other end.
Answer» A non uniform string of mass $45 kg$ and length $1.5 m$ has a variable linear mass density given by $μ = K x$ , where $x$ is the distance from one end of the string and $K$ is a constant. Tension in the string is $15 N$ (uniform). Find the time (in seconds) required for a pulse generated at one end of the string to travel to the other end.

Discussion

12.	A body is freely falling under the action of gravity. It covers half the total distance in the last second of its fall. If it falls for n second, then the value of n is
Answer» A body is freely falling under the action of gravity. It covers half the total distance in the last second of its fall. If it falls for $n$ second, then the value of $n$ is

Discussion

13.	Two balls of masses 3 kg and 5 kg are moving towards each other with speeds 5 m/s and 3 m/s respectively on a frictionless surface as shown in figure. After collision, the 5 kg ball retraces its path with speed 2 m/s. Find the coefficient of restitution.
Answer» Two balls of masses $3 kg$ and $5 kg$ are moving towards each other with speeds $5 m/s$ and $3 m/s$ respectively on a frictionless surface as shown in figure. After collision, the $5 kg$ ball retraces its path with speed $2 m/s$ . Find the coefficient of restitution.

Discussion

14.	In the arrangement shown in the figure, coefficient of friction between the two blocks is, μ=0.5. The force of friction acting between the two blocks is
Answer» In the arrangement shown in the figure, coefficient of friction between the two blocks is, $μ = 0.5$ . The force of friction acting between the two blocks is

Discussion

15.	The displacement x of a particle of mass m kg moving in one dimension is related to the time t by the equation t=4x+3 where x is in metre and t is in second. The work done by the force in the first six seconds in joules is
Answer» The displacement $x$ of a particle of mass $m kg$ moving in one dimension is related to the time $t$ by the equation $t = 4 x + 3$ where $x$ is in metre and $t$ is in second. The work done by the force in the first six seconds in joules is

Discussion

16.	A body of mass 0.01 kg executes simple harmonic motion (SHM) about x=0 under the influence of a force as shown in figure. The time period of the SHM is
Answer» A body of mass $0.01 kg$ executes simple harmonic motion (SHM) about $x = 0$ under the influence of a force as shown in figure. The time period of the SHM is

Discussion

17.	The velocity at the maximum height of a projectile is 12 times its initial velocity of projection (u). Its range on the horizontal plane is
Answer» The velocity at the maximum height of a projectile is $\frac{1}{2}$ times its initial velocity of projection $(u)$ . Its range on the horizontal plane is

Discussion

18.	Imagine that you are in a spacecraft orbiting around the earth in a circle of radius 7000km.(from the centre of the earth)if you decrease the magnitude of mechanical energy of the spacecraft with system by 10% firing rockets then what is the greatest height you can take your spacecraft above the surface of the earth (Re=6400km)
Answer» Imagine that you are in a spacecraft orbiting around the earth in a circle of radius 7000km.(from the centre of the earth)if you decrease the magnitude of mechanical energy of the spacecraft with system by 10% firing rockets then what is the greatest height you can take your spacecraft above the surface of the earth (Re=6400km)

Discussion

19.	Which of the following atoms in the ground state has the same total number of s electrons and p electrons?
Answer» Which of the following atoms in the ground state has the same total number of $s$ electrons and $p$ electrons?

Discussion

20.	Explain the working of a laser printer.
Answer» Explain the working of a laser printer.

Discussion

21.	If A, B, C and D are the points with position vectors ^i−^j+^k,2^i−^j+3^k and 3^i−2^j+^k respectively, then find the projection of →AB along →CD.
Answer» If A, B, C and D are the points with position vectors $^i -^j +^k, 2^i -^j + 3^k a n d 3^i - 2^j +^k$ respectively, then find the projection of $\to A B a l o n g \to C D$ .

Discussion

22.	The spring balance A reads 2kg with a block m suspended from it. A balance B reads 5 kg when a beaker with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid in the beaker as shown in the figure in this situation:
Answer» The spring balance A reads 2kg with a block m suspended from it. A balance B reads 5 kg when a beaker with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid in the beaker as shown in the figure in this situation:

22.

The spring balance A reads 2kg with a block m suspended from it. A balance B reads 5 kg when a beaker with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid in the beaker as shown in the figure in this situation:

Answer»

The spring balance A reads 2kg with a block m suspended from it. A balance B reads 5 kg when a beaker with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid in the beaker as shown in the figure in this situation:

Discussion

23.	If the speed of a car is given as v=4t−6 m/s, total distance covered by the car in 10 sec is
Answer» If the speed of a car is given as $v = 4 t - 6 m/s$ , total distance covered by the car in $10 s e c$ is

Discussion

24.	20 Nm torque is applied to a flywheel that rotates about a fixed axis and has moment of inertia of 25 kgm2. If the flywheel is initially at rest, what is its angular velocity after it has turned through 10 revolutions?
Answer» $20 Nm$ torque is applied to a flywheel that rotates about a fixed axis and has moment of inertia of $25 {kgm}^{2}$ . If the flywheel is initially at rest, what is its angular velocity after it has turned through $10$ revolutions?

Discussion

25.	If intensity of incident light is increased in PEE then which of the following is true
Answer» If intensity of incident light is increased in PEE then which of the following is true

Discussion

26.	A particle is falling freely under gravity. If in the first t seconds, it covers distance x1 and in the next t seconds, it covers distance x2, then t is given by
Answer» A particle is falling freely under gravity. If in the first $t$ seconds, it covers distance $x_{1}$ and in the next $t$ seconds, it covers distance $x_{2}$ , then $t$ is given by

Discussion

27.	Who sits between C and G?
Answer» Who sits between C and G?

Discussion

28.	The ratio of the energy of photon of 2000 Å wavelength radiation to that of 4000 Å radiation is
Answer» The ratio of the energy of photon of 2000 Å wavelength radiation to that of 4000 Å radiation is

Discussion

29.	A squre loop of side l, mass m and resistance R falls vertically into a uniform magnetic field directed perpendicular to the plane of the coil. One of the sides of the coil is always outside the magnetic field. The height h through which the loop falls so that it attains terminal velocity on entering the region of magnetic field is given by
Answer» A squre loop of side l, mass m and resistance R falls vertically into a uniform magnetic field directed perpendicular to the plane of the coil. One of the sides of the coil is always outside the magnetic field. The height h through which the loop falls so that it attains terminal velocity on entering the region of magnetic field is given by

Discussion

30.	the number of electric lines of force emerging out of a closed surface is 1000, then the charge enclosed by the surface is
Answer» the number of electric lines of force emerging out of a closed surface is 1000, then the charge enclosed by the surface is

Discussion

31.	The ‘rad’ is the correct unit used to report the measurement of
Answer» The ‘rad’ is the correct unit used to report the measurement of

Discussion

32.	Which of the following displacement time (x-t) graphs can possibly represent the one-dimensional motion of a particle?
Answer» Which of the following displacement time (x-t) graphs can possibly represent the one-dimensional motion of a particle?

Discussion

33.	A black body is at a temperature of 2880 K. The energy of radiation emitted by this object with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm is U3. The Wein's constant b = 2.88 x 106 nm K. Then
Answer» A black body is at a temperature of 2880 K. The energy of radiation emitted by this object with wavelength between 499 nm and 500 nm is $U_{1}$ , between 999 nm and 1000 nm is $U_{2}$ and between 1499 nm and 1500 nm is $U_{3}$ . The Wein's constant b = 2.88 x $10^{6}$ nm K. Then

Discussion

34.	The edges of a parallelepiped are given by the vectors (2 ^i+3^j+4^k), 4^j and 5^j+m^k. What should be the value of m in order that the volume of the parallelepiped be 24?
Answer» The edges of a parallelepiped are given by the vectors $(2^i + 3^j + 4^k), 4^j$ and $5^j + m^k .$ What should be the value of $m$ in order that the volume of the parallelepiped be 24?

Discussion

35.	Two towers AB and CD are situated at a distance d apart. An object of mass m is thrown from the top of AB horizontally with a velocity of 10 m/s towards CD. Simultaneously another object of mass 2 m is thrown from the top of CD at an angle 60∘ with the horizontal towards AB with the same magnitude of initial velocity as that of the first object. The two objects move in the same vertical plane, collide in mid-air and stick with each other. Find the distance between the foot of the towers (approximately).
Answer» Two towers AB and CD are situated at a distance $d$ apart. An object of mass $m$ is thrown from the top of AB horizontally with a velocity of $10 m / s$ towards CD. Simultaneously another object of mass $2 m$ is thrown from the top of CD at an angle $60^{\circ}$ with the horizontal towards AB with the same magnitude of initial velocity as that of the first object. The two objects move in the same vertical plane, collide in mid-air and stick with each other. Find the distance between the foot of the towers (approximately).

Discussion

36.	A ball of mass 150 g moving at 10 ms-1 is stopped by a force which acts on it for 0.1 s, then the impulsive force is
Answer» A ball of mass 150 g moving at 10 ms^-1 is stopped by a force which acts on it for 0.1 s, then the impulsive force is

36.

A ball of mass 150 g moving at 10 ms-1 is stopped by a force which acts on it for 0.1 s, then the impulsive force is

Answer»

A ball of mass 150 g moving at 10 ms^-1 is stopped by a force which acts on it for 0.1 s, then the impulsive force is

Discussion

37.	A convex lens A of focal length 20 cm and a concave lens B of focal length 5 cm are kept along the same axis with a distace d between them. If a parallel beam of light falling on A leaves B as a parallel beam, then d is equal to (IIT-JEE 1985)
Answer» A convex lens A of focal length 20 cm and a concave lens B of focal length 5 cm are kept along the same axis with a distace d between them. If a parallel beam of light falling on A leaves B as a parallel beam, then d is equal to (IIT-JEE 1985)

Discussion

38.	In the figure shown below, mA=2 kg and mB=3 kg. A force F=40 N is applied on 2 kg block as shown. Find the acceleration of COM of the system. (Neglect friction everywhere and assume the string to be inextensible)
Answer» In the figure shown below, $m_{A} = 2 kg$ and $m_{B} = 3 kg$ . A force $F = 40 N$ is applied on $2 kg$ block as shown. Find the acceleration of COM of the system. (Neglect friction everywhere and assume the string to be inextensible)

Discussion

39.	Two mirrors are inclined at an angle θ as shown in the figure. A light ray is incident parallel to one of the mirrors. What should be the value of θ such that the light will retrace its path after the third reflection?
Answer» Two mirrors are inclined at an angle $θ$ as shown in the figure. A light ray is incident parallel to one of the mirrors. What should be the value of $θ$ such that the light will retrace its path after the third reflection?

Discussion

40.	Three equal charges are placed on the three corners of a square. If the force between q1 and q2 is F12 and that between q1 and q3 is F13, the ratio of magnitudes F12F13 is
Answer» Three equal charges are placed on the three corners of a square. If the force between $q_{1}$ and $q_{2}$ is $F_{12}$ and that between $q_{1}$ and $q_{3}$ is $F_{13}$ , the ratio of magnitudes $\frac{F_{12}}{F_{13}}$ is

Discussion

41.	A man (mass=50 kg) and his son (mass=20 kg) are standing on a frictionless surface facing each other. The man pushes his son, so that he starts moving at a speed of 0.70 ms−1 with respect to the man. The speed of the man with respect to the surface is
Answer» A man $(mass = 50 kg)$ and his son $(mass = 20 kg)$ are standing on a frictionless surface facing each other. The man pushes his son, so that he starts moving at a speed of $0.70 {ms}^{- 1}$ with respect to the man. The speed of the man with respect to the surface is

Discussion

42.	Assume that a car is able to stop with a retardation of 8 m/s2 and that a driver can react to an emergency in 0.5 sec. Calculate the overall stopping distance of the car for a speed of 72 km/hr of the car
Answer» Assume that a car is able to stop with a retardation of $8 {m/s}^{2}$ and that a driver can react to an emergency in $0.5 sec$ . Calculate the overall stopping distance of the car for a speed of $72 km/hr$ of the car

Discussion

43.	A neutron initially at rest,decays into a proton,an electron and an antineutrino. The ejected electron has a momentum of 1.4×10−26 kg−ms and the antinuetrino 6.4×10−27 kg−ms.Find the recoil speed of the proton (a) if the electron and the antineutrino are ejected along the same direction and (b) if they are ejected along perpendicular directions.Mass of the proton =1.67×10−27 kg.
Answer» A neutron initially at rest,decays into a proton,an electron and an antineutrino. The ejected electron has a momentum of $1.4 \times 10^{- 26} k g - \frac{m}{s}$ and the antinuetrino $6.4 \times 10^{- 27} k g - \frac{m}{s}$ .Find the recoil speed of the proton (a) if the electron and the antineutrino are ejected along the same direction and (b) if they are ejected along perpendicular directions.Mass of the proton = $1.67 \times 10^{- 27} k g$ .

Discussion

44.	A particle of mass 10g is describing S.H.M along a straight line with period of 2s and amplitude of 10cm. Its kinetic energy when it is at 5cm from its equilibrium position is
Answer» A particle of mass 10g is describing S.H.M along a straight line with period of 2s and amplitude of 10cm. Its kinetic energy when it is at 5cm from its equilibrium position is

Discussion

45.	A U shaped tube of mass 2m is placed on a smooth horizontal surface. Two identical spherical balls each of mass m and of diameter slightly less than the inner diameter of tube enters into the tube with a velocity u as shown. (Assume no loss of energy anywhere and all collisions to be elastic). Speed of each spherical ball, just before their collision is
Answer» A U shaped tube of mass 2m is placed on a smooth horizontal surface. Two identical spherical balls each of mass m and of diameter slightly less than the inner diameter of tube enters into the tube with a velocity u as shown. (Assume no loss of energy anywhere and all collisions to be elastic). Speed of each spherical ball, just before their collision is

45.

A U shaped tube of mass 2m is placed on a smooth horizontal surface. Two identical spherical balls each of mass m and of diameter slightly less than the inner diameter of tube enters into the tube with a velocity u as shown. (Assume no loss of energy anywhere and all collisions to be elastic). Speed of each spherical ball, just before their collision is

Answer»

A U shaped tube of mass 2m is placed on a smooth horizontal surface. Two identical spherical balls each of mass m and of diameter slightly less than the inner diameter of tube enters into the tube with a velocity u as shown. (Assume no loss of energy anywhere and all collisions to be elastic).

Speed of each spherical ball, just before their collision is

Discussion

46.	If the critical constants for a hypothetical gas are Vc=150 cm3 mol−1, Pc=50 atm and Tc=300K. Then the radius of the molecule is: [Take R=112 L atm mol−1K−1]
Answer» If the critical constants for a hypothetical gas are $V_{c} = 150 c m^{3} m o l^{- 1}, P_{c} = 50 a t m$ and $T_{c} = 300 K$ . Then the radius of the molecule is: [Take $R = \frac{1}{12} {L atm mol}^{- 1} K^{- 1}$ ]

Discussion

47.	Which molecules, ice at zero degree Celsius or water have greater potential energy and why?
Answer» Which molecules, ice at zero degree Celsius or water have greater potential energy and why?

Discussion

48.	Find the acceleration of the moon with respect to the earth from the following data : Diistance between the earth and the moon = 3.85×105km and the time taken by the moon to complete one revolution around the earth = 27.3 days.
Answer» Find the acceleration of the moon with respect to the earth from the following data : Diistance between the earth and the moon = $3.85 \times 10^{5}$ km and the time taken by the moon to complete one revolution around the earth = 27.3 days.

Discussion

49.	When a block of mass M is suspended by a long wire of length L, the length of the wire becomes L+l. The elastic potential energy stored in the extended wire is
Answer» When a block of mass M is suspended by a long wire of length L, the length of the wire becomes L+l. The elastic potential energy stored in the extended wire is

49.

When a block of mass M is suspended by a long wire of length L, the length of the wire becomes L+l. The elastic potential energy stored in the extended wire is

Answer»

When a block of mass M is suspended by a long wire of length L, the length of the wire becomes L+l. The elastic potential energy stored in the extended wire is

Discussion

50.	A particle on earth's surface is given a velocity equal to its escape velocity. Its total mechanical energy will be
Answer» A particle on earth's surface is given a velocity equal to its escape velocity. Its total mechanical energy will be

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Four point masses, each of value m, are placed at the corners of a square ABCD of side l. The moment of inertia of this system about an axis passing through A and parallel to BD is

Neglecting the density of air, the terminal velocity obtained by a raindrop of radius 0.3 mm falling through the air of viscosity 1.8×10−5 Ns/m2 will be (ρwater=103kg/m3)

A plane-convex lens fits exactly into a plane-concave lens. Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive index μ1 and μ2 and R is the radius of curvature of the curved surface of the lenses, then the focal length of the combination is

In the circuit shown the capacitor is initially charged with a 12 V battery, when switch S1 is open and switch S2 is closed. S1 is then closed and, at the same time, S2 is opened. The maximum value of current in the circuit is:

Write a relation for polarisation→P of a dielectric material in the presence of an external electric field →E

A body of mass 600 gm is attached to a spring of spring constant k=100 N/m and it is performing damped oscillations. If damping constant is 0.2 and driving force is F=F0cos(ωt) where F0=20 N, find the amplitude of oscillations at resonance.

Three particles of same mass m are attached by massless rods of same length l and placed at the vertices of an equilateral triangle. The angular momentum about an axis XX′ will be nmωl24, where n is

A body is freely falling under the action of gravity. It covers half the total distance in the last second of its fall. If it falls for n second, then the value of n is

Two balls of masses 3 kg and 5 kg are moving towards each other with speeds 5 m/s and 3 m/s respectively on a frictionless surface as shown in figure. After collision, the 5 kg ball retraces its path with speed 2 m/s. Find the coefficient of restitution.

In the arrangement shown in the figure, coefficient of friction between the two blocks is, μ=0.5. The force of friction acting between the two blocks is

The displacement x of a particle of mass m kg moving in one dimension is related to the time t by the equation t=4x+3 where x is in metre and t is in second. The work done by the force in the first six seconds in joules is

A body of mass 0.01 kg executes simple harmonic motion (SHM) about x=0 under the influence of a force as shown in figure. The time period of the SHM is

The velocity at the maximum height of a projectile is 12 times its initial velocity of projection (u). Its range on the horizontal plane is

Which of the following atoms in the ground state has the same total number of s electrons and p electrons?

Explain the working of a laser printer.

If A, B, C and D are the points with position vectors ^i−^j+^k,2^i−^j+3^k and 3^i−2^j+^k respectively, then find the projection of →AB along →CD.

The spring balance A reads 2kg with a block m suspended from it. A balance B reads 5 kg when a beaker with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid in the beaker as shown in the figure in this situation:

If the speed of a car is given as v=4t−6 m/s, total distance covered by the car in 10 sec is

20 Nm torque is applied to a flywheel that rotates about a fixed axis and has moment of inertia of 25 kgm2. If the flywheel is initially at rest, what is its angular velocity after it has turned through 10 revolutions?

If intensity of incident light is increased in PEE then which of the following is true

A particle is falling freely under gravity. If in the first t seconds, it covers distance x1 and in the next t seconds, it covers distance x2, then t is given by

Who sits between C and G?

The ratio of the energy of photon of 2000 Å wavelength radiation to that of 4000 Å radiation is

the number of electric lines of force emerging out of a closed surface is 1000, then the charge enclosed by the surface is

The ‘rad’ is the correct unit used to report the measurement of

Which of the following displacement time (x-t) graphs can possibly represent the one-dimensional motion of a particle?

A black body is at a temperature of 2880 K. The energy of radiation emitted by this object with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm is U3. The Wein's constant b = 2.88 x 106 nm K. Then

The edges of a parallelepiped are given by the vectors (2 ^i+3^j+4^k), 4^j and 5^j+m^k. What should be the value of m in order that the volume of the parallelepiped be 24?

A ball of mass 150 g moving at 10 ms-1 is stopped by a force which acts on it for 0.1 s, then the impulsive force is

A convex lens A of focal length 20 cm and a concave lens B of focal length 5 cm are kept along the same axis with a distace d between them. If a parallel beam of light falling on A leaves B as a parallel beam, then d is equal to (IIT-JEE 1985)

In the figure shown below, mA=2 kg and mB=3 kg. A force F=40 N is applied on 2 kg block as shown. Find the acceleration of COM of the system. (Neglect friction everywhere and assume the string to be inextensible)

Two mirrors are inclined at an angle θ as shown in the figure. A light ray is incident parallel to one of the mirrors. What should be the value of θ such that the light will retrace its path after the third reflection?

Three equal charges are placed on the three corners of a square. If the force between q1 and q2 is F12 and that between q1 and q3 is F13, the ratio of magnitudes F12F13 is

A man (mass=50 kg) and his son (mass=20 kg) are standing on a frictionless surface facing each other. The man pushes his son, so that he starts moving at a speed of 0.70 ms−1 with respect to the man. The speed of the man with respect to the surface is

Assume that a car is able to stop with a retardation of 8 m/s2 and that a driver can react to an emergency in 0.5 sec. Calculate the overall stopping distance of the car for a speed of 72 km/hr of the car

A particle of mass 10g is describing S.H.M along a straight line with period of 2s and amplitude of 10cm. Its kinetic energy when it is at 5cm from its equilibrium position is

If the critical constants for a hypothetical gas are Vc=150 cm3 mol−1, Pc=50 atm and Tc=300K. Then the radius of the molecule is: [Take R=112 L atm mol−1K−1]

Which molecules, ice at zero degree Celsius or water have greater potential energy and why?

Find the acceleration of the moon with respect to the earth from the following data : Diistance between the earth and the moon = 3.85×105km and the time taken by the moon to complete one revolution around the earth = 27.3 days.

When a block of mass M is suspended by a long wire of length L, the length of the wire becomes L+l. The elastic potential energy stored in the extended wire is

A particle on earth's surface is given a velocity equal to its escape velocity. Its total mechanical energy will be