2673 + Interview Questions in Physics Page 13 InterviewSolution

601.	Two conical portions each of height 2R are removed from a cylinder of length 4R and radius R as shown in figure. If density of the material is ρ, then moment of inertia of given system about the axis of cylinder is
Answer» Two conical portions each of height 2R are removed from a cylinder of length 4R and radius R as shown in figure. If density of the material is $ρ,$ then moment of inertia of given system about the axis of cylinder is

Discussion

602.	An ideal massless spring can be compressed 1 m by a force of 100 N. This same spring is placed at the bottom of a frictionless inclined plane which makes an angle θ=30∘ with the horizontal. A 10 kg mass is released from rest at the top of the incline and is brought to rest momentarily after compressing the spring 2 meters.(a) Through what distance does the mass slide before coming to rest?(b) What is the speed of the mass just before it reaches the spring?
Answer» An ideal massless spring can be compressed 1 m by a force of 100 N. This same spring is placed at the bottom of a frictionless inclined plane which makes an angle $θ = 30^{\circ}$ with the horizontal. A 10 kg mass is released from rest at the top of the incline and is brought to rest momentarily after compressing the spring 2 meters. (a) Through what distance does the mass slide before coming to rest? (b) What is the speed of the mass just before it reaches the spring?

Discussion

603.	Unpolarised light of intensity 32Wm−2 passes through three polarisers such that the transmission axis of the last polarizer is perpendicular to that of the first. At what angle will the transmitted intensity be maximum?
Answer» Unpolarised light of intensity $32 W m^{- 2}$ passes through three polarisers such that the transmission axis of the last polarizer is perpendicular to that of the first. At what angle will the transmitted intensity be maximum?

Discussion

604.	Block A and B in the figure are connected by a bar of negligible weight. If A=B=170 kg and μA=0.2 and μB=0.4, where μA and μB are the coefficients of limiting friction between the blocks and the plane, calculate the contact force on the bar due to A (g=10 m/s2)
Answer» Block $A$ and $B$ in the figure are connected by a bar of negligible weight. If $A = B = 170 kg$ and $μ_{A} = 0.2$ and $μ_{B} = 0.4$ , where $μ_{A}$ and $μ_{B}$ are the coefficients of limiting friction between the blocks and the plane, calculate the contact force on the bar due to $A$ $(g = 10 {m/s}^{2})$

Discussion

605.	Two bombs A and B are projected in air. A is thrown with a speed of 30 m/s and B with a speed of 40 m/s as shown in the figure. What is the separation between them after t s ?
Answer» Two bombs $A$ and $B$ are projected in air. $A$ is thrown with a speed of $30 m/s$ and $B$ with a speed of $40 m/s$ as shown in the figure. What is the separation between them after $t s$ ?

Discussion

606.	A circular spring of natural length l is cut and welded with two beads of masses m1 and m2 such that the ratio of the lengths of the springs between the beads is 4:1. If the stiffness of the original spring is k, then find the angular frequency of oscillation of the beads in a smooth horizontal rigid tube.[Assume m1=m and m2=3m].
Answer» A circular spring of natural length $l$ is cut and welded with two beads of masses $m_{1}$ and $m_{2}$ such that the ratio of the lengths of the springs between the beads is $4 : 1$ . If the stiffness of the original spring is $k$ , then find the angular frequency of oscillation of the beads in a smooth horizontal rigid tube. [Assume $m_{1} = m$ and $m_{2} = 3 m$ ].

Discussion

607.	Find the center of mass with respect to 0, of uniform semicircular wire of mass M and Radius R (as shown in figure)
Answer» Find the center of mass with respect to 0, of uniform semicircular wire of mass M and Radius R (as shown in figure)

607.

Find the center of mass with respect to 0, of uniform semicircular wire of mass M and Radius R (as shown in figure)

Answer»

Find the center of mass with respect to 0, of uniform semicircular wire of mass M and Radius R (as shown in figure)

Discussion

608.	A square coil of N turns (with length of each side equal L) carrying current i is placed in a uniform magnetic field →B=B0^j as shown in figure. What is the torque acting on the coil
Answer» A square coil of N turns (with length of each side equal L) carrying current i is placed in a uniform magnetic field $\to B = B_{0}^j$ as shown in figure. What is the torque acting on the coil

Discussion

609.	The temperature T of one mole of an ideal gas varies with its volume V as T=−αV3+βV2, where α and β are positive constants. The maximum pressure of the gas during this process is
Answer» The temperature $T$ of one mole of an ideal gas varies with its volume $V$ as $T = - α V^{3} + β V^{2}$ , where $α$ and $β$ are positive constants. The maximum pressure of the gas during this process is

Discussion

610.	A body of mass 20 kg is kept on a rough horizontal surface. If μs=0.5 and an external force of F=50 N is applied on the body, find the contact force on the body. (Take g=10 m/s2)
Answer» A body of mass $20 k g$ is kept on a rough horizontal surface. If $μ_{s} = 0.5$ and an external force of $F = 50 N$ is applied on the body, find the contact force on the body. (Take $g = 10 m / s^{2}$ )

Discussion

611.	∫(sec2x+e3x)dx is equals to
Answer» $\int (s e c^{2} x + e^{3 x}) d x$ is equals to

Discussion

612.	An alternating current is given by the equation i=i1 cos ωt+i2 sin ω t. The r.m.s. current is given by
Answer» An alternating current is given by the equation $i = i_{1} c o s ω t + i_{2} s i n ω t$ . The r.m.s. current is given by

Discussion

613.	A rod of mass 2 m moves vertically downward on the surface of wedge of mass as shown in the figure. Find the relation between velocity of rod and that of the wedge at any instant.
Answer» A rod of mass $2 m$ moves vertically downward on the surface of wedge of mass as shown in the figure. Find the relation between velocity of rod and that of the wedge at any instant.

Discussion

614.	Consider the situation shown in figure. The system is released from rest and the block of mass 1.0 kg is found to have a speed 0.3 ms after it has descended through a distance of 1m. Find the coefficient of kinetic friction between the block and the table.
Answer» Consider the situation shown in figure. The system is released from rest and the block of mass 1.0 kg is found to have a speed 0.3 $\frac{m}{s}$ after it has descended through a distance of 1m. Find the coefficient of kinetic friction between the block and the table.

614.

Consider the situation shown in figure. The system is released from rest and the block of mass 1.0 kg is found to have a speed 0.3 ms after it has descended through a distance of 1m. Find the coefficient of kinetic friction between the block and the table.

Answer»

Consider the situation shown in figure. The system is released from rest and the block of mass 1.0 kg is found to have a speed 0.3 $\frac{m}{s}$ after it has descended through a distance of 1m. Find the coefficient of kinetic friction between the block and the table.

Discussion

615.	What will be the velocity of block A in the arrangement shown ?
Answer» What will be the velocity of block A in the arrangement shown ?

Discussion

616.	In the propagation of electromagnetic waves, the angle between the direction of propagation and plane of polarization is
Answer» In the propagation of electromagnetic waves, the angle between the direction of propagation and plane of polarization is

Discussion

617.	A dielectric slab of constant k = 3 is inserted inside gap of parallel plate capacitor of plate area L×L and separation of d at speed u. Power dissipation across resistance R is
Answer» A dielectric slab of constant k = 3 is inserted inside gap of parallel plate capacitor of plate area $L \times L$ and separation of d at speed u. Power dissipation across resistance R is

Discussion

618.	A block of mass 10 kg is kept on an inclined plane having an angle of inclination 37∘ attached with a spring of force constant 20 N/m as shown in the figure. If the coefficient of friction between block and incline is 0.8, then the maximum value of elongation for which the block is in contact with the inclined plane and has no slipping is
Answer» A block of mass $10 k g$ is kept on an inclined plane having an angle of inclination $37^{\circ}$ attached with a spring of force constant $20 N / m$ as shown in the figure. If the coefficient of friction between block and incline is $0.8$ , then the maximum value of elongation for which the block is in contact with the inclined plane and has no slipping is

Discussion

619.	The heat produced in a wire carrying an eletric current depends on the current, the resistance and thetime. Assuming that the dependence is of the product of powers type, guess an equation between thesequantities using dimensional analysis. The dimensional formula of resistance is ML2I−2T−3and heat is a form of energy.
Answer» The heat produced in a wire carrying an eletric current depends on the current, the resistance and the time. Assuming that the dependence is of the product of powers type, guess an equation between these quantities using dimensional analysis. The dimensional formula of resistance is $M L^{2} I^{- 2} T^{- 3}$ and heat is a form of energy.

619.

The heat produced in a wire carrying an eletric current depends on the current, the resistance and thetime. Assuming that the dependence is of the product of powers type, guess an equation between thesequantities using dimensional analysis. The dimensional formula of resistance is ML2I−2T−3and heat is a form of energy.

Answer»

The heat produced in a wire carrying an eletric current depends on the current, the resistance and the

time. Assuming that the dependence is of the product of powers type, guess an equation between these

quantities using dimensional analysis. The dimensional formula of resistance is $M L^{2} I^{- 2} T^{- 3}$ and heat is a

form of energy.

Discussion

620.	A body of mass m kg. starts falling from a point 2R above the earth’s surface. Its kinetic energy when it has fallen to a point ‘R’ above the eart’s surface [R – Radius of earth, M – Mass of earth, G – Gravitational constant]
Answer» A body of mass m kg. starts falling from a point 2R above the earth’s surface. Its kinetic energy when it has fallen to a point ‘R’ above the eart’s surface [R – Radius of earth, M – Mass of earth, G – Gravitational constant]

Discussion

621.	Find the ratio of tension T1 and T2 in the string as shown in figure if the whole system is moving with constant acceleration of 4 m/s2 under the influence of force of magnitude 220 N acting on block of mass 15 kg . Assume the coefficient of friction to be μ=1/3 and g=10 m/s2.
Answer» Find the ratio of tension $T_{1}$ and $T_{2}$ in the string as shown in figure if the whole system is moving with constant acceleration of $4 m / s^{2}$ under the influence of force of magnitude $220 N$ acting on block of mass $15 k g$ . Assume the coefficient of friction to be $μ = 1 / 3$ and $g = 10 m / s^{2}$ .

Discussion

622.	A bullet of mass 200 g fired with a velocity of 200 m/s, hits a block of mass 2 kg moving with a velocity of 10 m/s. After hitting the block, the bullet lodges into it. What is the velocity of the combined system? Assume that the collision is perfectly inelastic.
Answer» A bullet of mass $200 g$ fired with a velocity of $200 m/s$ , hits a block of mass $2 kg$ moving with a velocity of $10 m/s$ . After hitting the block, the bullet lodges into it. What is the velocity of the combined system? Assume that the collision is perfectly inelastic.

Discussion

623.	Calculate the force required to lift a load of 60 N, placed at a distance of 3 m from the fulcrum, if the effort is applied at a distance of 6 cm from the fulcrum.
Answer» Calculate the force required to lift a load of $60 N$ , placed at a distance of $3 m$ from the fulcrum, if the effort is applied at a distance of $6 cm$ from the fulcrum.

Discussion

624.	The normals drawn on a concave mirror
Answer» The normals drawn on a concave mirror

Discussion

625.	A capacitor having an initial charge 0.1 C, is discharging in a simple RC circuit with the time constant 3 seconds. How much charge will remain after 6 sec?
Answer» A capacitor having an initial charge 0.1 C, is discharging in a simple RC circuit with the time constant 3 seconds. How much charge will remain after 6 sec?

Discussion

626.	A thin uniform rod of mass 10 kg and length 6 m is rotating about an axis perpendicular to its plane, passing through the midpoint of the rod. Find the moment of inertia of the rod about this axis.
Answer» A thin uniform rod of mass $10 kg$ and length $6 m$ is rotating about an axis perpendicular to its plane, passing through the midpoint of the rod. Find the moment of inertia of the rod about this axis.

Discussion

627.	Find the resistance of a hollow sphere whose inner surface (radius :a) and outer surface (radius b) are connected to a p.d E(ρ:resistivity)
Answer» Find the resistance of a hollow sphere whose inner surface (radius :a) and outer surface (radius b) are connected to a p.d E( $ρ$ :resistivity)

Discussion

628.	Each condenser in the figure shown has a capacity of 3 μF. The equivalent capacity between the terminals A and B is
Answer» Each condenser in the figure shown has a capacity of 3 μF. The equivalent capacity between the terminals A and B is

628.

Each condenser in the figure shown has a capacity of 3 μF. The equivalent capacity between the terminals A and B is

Answer»

Each condenser in the figure shown has a capacity of 3 μF. The equivalent capacity between the terminals A and B is

Discussion

629.	The eyepiece of a refracting telescope has f=9 cm. In the normal setting, seperation between objective and eyepiece is 1.8 m. Find the magnification.
Answer» The eyepiece of a refracting telescope has $f = 9 cm$ . In the normal setting, seperation between objective and eyepiece is $1.8 m$ . Find the magnification.

Discussion

630.	Ball A of mass 10 kg moving with a velocity 6 m/s, collides with ball B of mass 50 kg which is at rest. What is the ratio of the kinetic energies of the ball A before and after the elastic collision?
Answer» Ball $A$ of mass $10 kg$ moving with a velocity $6 m/s$ , collides with ball $B$ of mass $50 kg$ which is at rest. What is the ratio of the kinetic energies of the ball $A$ before and after the elastic collision?

Discussion

631.	Find the minimum value of coefficient of friction between the 4 kg block and the surface for the system to be at rest for the figure shown.
Answer» Find the minimum value of coefficient of friction between the $4 k g$ block and the surface for the system to be at rest for the figure shown.

Discussion

632.	A stationary person observes that rain is falling vertically down at 18 km/hr. A cyclist is moving in positive x- direction on the level road, at 24 km/hr. At what angle from the horizontal should the cyclist hold his umbrella to protect himself from rain?
Answer» A stationary person observes that rain is falling vertically down at $18 km/hr$ . A cyclist is moving in positive x- direction on the level road, at $24 km/hr$ . At what angle from the horizontal should the cyclist hold his umbrella to protect himself from rain?

Discussion

633.	A parachutist drops first freely from an airplane for 10 s and then the parachute opens out. Now he descends with net retardation of 2.5 m/s2. If he bails out of the plane at a height of 2495 m and g=10 m/s2, his velocity on reaching the ground will be
Answer» A parachutist drops first freely from an airplane for $10 s$ and then the parachute opens out. Now he descends with net retardation of $2.5 m / s^{2}$ . If he bails out of the plane at a height of $2495 m$ and $g = 10 m / s^{2}$ , his velocity on reaching the ground will be

Discussion

634.	In the figure shown, find the tension in the string connecting the blocks of mass 2 kg and 3 kg. Take g=10 m/s2
Answer» In the figure shown, find the tension in the string connecting the blocks of mass $2 k g$ and $3 k g$ . Take $g = 10 m / s^{2}$

Discussion

635.	Two coherent sources of light can be obtained by[MH CET 2001]
Answer» Two coherent sources of light can be obtained by [MH CET 2001]

635.

Two coherent sources of light can be obtained by[MH CET 2001]

Answer»

Two coherent sources of light can be obtained by

[MH CET 2001]

Discussion

636.	A ball of mass 'm', moving with a velocity 'v' along X-axis, strikes another ball of mass '2m' kept at rest. The first ball comes to rest after collision and the other breaks into two equal pieces. One of the pieces starts moving along Y-axis with a speed v1. What will be the velocity of the other piece?
Answer» A ball of mass 'm', moving with a velocity 'v' along X-axis, strikes another ball of mass '2m' kept at rest. The first ball comes to rest after collision and the other breaks into two equal pieces. One of the pieces starts moving along Y-axis with a speed $v_{1}$ . What will be the velocity of the other piece?

Discussion

637.	The acceleration of A is as shown in the figure. If the system starts from rest, find the velocity with which the wedge hits the wall. A is constrained to move only in vertical direction.
Answer» The acceleration of $A$ is as shown in the figure. If the system starts from rest, find the velocity with which the wedge hits the wall. $A$ is constrained to move only in vertical direction.

Discussion

638.	The de Broglie wavelength of an electron moving with a velocity 0f 1.5X108 m/s is equal to that of a photon. The ratio of kinetic energy of that electron to the photon is.[IIT JEE 2004]
Answer» The de Broglie wavelength of an electron moving with a velocity 0f $1.5 X 10^{8}$ m/s is equal to that of a photon. The ratio of kinetic energy of that electron to the photon is. [IIT JEE 2004]

Discussion

639.	Two wires of the same material (Young's modulus Y) and same length L but radii R and 2R respectively are joined end to end and a weight w is suspended from the combination as shown in the figure. The elastic potential energy stored in the system is
Answer» Two wires of the same material (Young's modulus $Y$ ) and same length $L$ but radii $R$ and $2 R$ respectively are joined end to end and a weight $w$ is suspended from the combination as shown in the figure. The elastic potential energy stored in the system is

Discussion

640.	A particle P is sliding down a frictionless hemispherical bowl. It passes the point A at t = 0. At this instant of time, the horizontal component of its velocity is v. A bead Q of the same mass as P is ejected from A at t = 0 along the horizontal string AB, with a speed v. Friction between the bead and the string may be neglected. Let tp and tq be the respective times taken by P and Q to reach the point B. Then IIT-JEE 1993
Answer» A particle P is sliding down a frictionless hemispherical bowl. It passes the point A at t = 0. At this instant of time, the horizontal component of its velocity is v. A bead Q of the same mass as P is ejected from A at t = 0 along the horizontal string AB, with a speed v. Friction between the bead and the string may be neglected. Let $t_{p}$ and $t_{q}$ be the respective times taken by P and Q to reach the point B. Then IIT-JEE 1993

640.

A particle P is sliding down a frictionless hemispherical bowl. It passes the point A at t = 0. At this instant of time, the horizontal component of its velocity is v. A bead Q of the same mass as P is ejected from A at t = 0 along the horizontal string AB, with a speed v. Friction between the bead and the string may be neglected. Let tp and tq be the respective times taken by P and Q to reach the point B. Then IIT-JEE 1993

Answer»

A particle P is sliding down a frictionless hemispherical bowl. It passes the point A at t = 0. At this instant of time, the horizontal component of its velocity is v. A bead Q of the same mass as P is ejected from A at t = 0 along the horizontal string AB, with a speed v. Friction between the bead and the string may be neglected. Let $t_{p}$ and $t_{q}$ be the respective times taken by P and Q to reach the point B. Then IIT-JEE 1993

Discussion

641.	The cut-in voltage for silicon diode is approximately
Answer» The cut-in voltage for silicon diode is approximately

Discussion

642.	A block of mass m is located on a horizontal plane. The block acquires a horizontal velocity v0 due to friction. Find the mean power developed by the friction force during the motion of the body. The frictional cofficient is μ=0.3,m=2 kg and v0=5 m/s (Take g=10 m/s2)
Answer» A block of mass $m$ is located on a horizontal plane. The block acquires a horizontal velocity $v_{0}$ due to friction. Find the mean power developed by the friction force during the motion of the body. The frictional cofficient is $μ = 0.3, m = 2 kg$ and $v_{0} = 5 m/s$ (Take $g = 10 {m/s}^{2}$ )

Discussion

643.	Two masses m1=1 kg and m2=0.5 kg are suspended together by a massless spring of spring constant 12.5 N/m. When masses are in equilibrium, m1 is removed without disturbing the system. New amplitude of oscillation will be
Answer» Two masses $m_{1} = 1 kg$ and $m_{2} = 0.5 kg$ are suspended together by a massless spring of spring constant $12.5 N/m$ . When masses are in equilibrium, $m_{1}$ is removed without disturbing the system. New amplitude of oscillation will be

Discussion

644.	Quantum nature of light is explained by which of the following phenomenon
Answer» Quantum nature of light is explained by which of the following phenomenon

Discussion

645.	The photoelectric effect can be understood on the basis of
Answer» The photoelectric effect can be understood on the basis of

Discussion

646.	If pressure at half the depth of a lake is equal to 2/3 pressure at the bottom of the lake then what is the depth of the lake
Answer» If pressure at half the depth of a lake is equal to 2/3 pressure at the bottom of the lake then what is the depth of the lake

646.

If pressure at half the depth of a lake is equal to 2/3 pressure at the bottom of the lake then what is the depth of the lake

Answer»

If pressure at half the depth of a lake is equal to 2/3 pressure at the bottom of the lake then what is the depth of the lake

Discussion

647.	A ball is thrown from a point with a speed v0 at an angle of projection θ. From the same point and at the same instant a person starts running with a constant speed v02 to catch the ball. Will the person be able to catch the ball? If yes, what should be the angle of projection
Answer» A ball is thrown from a point with a speed $v_{0}$ at an angle of projection $θ$ . From the same point and at the same instant a person starts running with a constant speed $\frac{v_{0}}{2}$ to catch the ball. Will the person be able to catch the ball? If yes, what should be the angle of projection

Discussion

648.	A particle is moving with speed v=b√x along the positive x - axis. Calculate the speed of the particle at time t=τ. (Assume that the particle is at the origin at t=0).
Answer» A particle is moving with speed $v = b \sqrt{x}$ along the positive $x$ - axis. Calculate the speed of the particle at time $t = τ$ . (Assume that the particle is at the origin at $t = 0$ ).

Discussion

649.	A juggler is juggling 7 balls simultaneously. If the time gap to pass ball from one hand to the other is 2 second then find the maximum height attained by each ball.
Answer» A juggler is juggling $7$ balls simultaneously. If the time gap to pass ball from one hand to the other is $2$ second then find the maximum height attained by each ball.

Discussion

650.	A concave mirror forms a real image of a point source lying on the optical axis at a distance of 50 cm from the mirror. The focal length of the mirror is 25 cm. The mirror is cut into two equal parts and each of the two halves are rotated about S by 90∘, one in anticlockwise and other in clockwise with reference to the original position, then the distance between the two images formed by each part will be
Answer» A concave mirror forms a real image of a point source lying on the optical axis at a distance of $50 cm$ from the mirror. The focal length of the mirror is $25 cm$ . The mirror is cut into two equal parts and each of the two halves are rotated about $S$ by $90^{\circ}$ , one in anticlockwise and other in clockwise with reference to the original position, then the distance between the two images formed by each part will be

Discussion

Explore topic-wise InterviewSolutions in .

Two conical portions each of height 2R are removed from a cylinder of length 4R and radius R as shown in figure. If density of the material is ρ, then moment of inertia of given system about the axis of cylinder is

Unpolarised light of intensity 32Wm−2 passes through three polarisers such that the transmission axis of the last polarizer is perpendicular to that of the first. At what angle will the transmitted intensity be maximum?

Block A and B in the figure are connected by a bar of negligible weight. If A=B=170 kg and μA=0.2 and μB=0.4, where μA and μB are the coefficients of limiting friction between the blocks and the plane, calculate the contact force on the bar due to A (g=10 m/s2)

Two bombs A and B are projected in air. A is thrown with a speed of 30 m/s and B with a speed of 40 m/s as shown in the figure. What is the separation between them after t s ?

Find the center of mass with respect to 0, of uniform semicircular wire of mass M and Radius R (as shown in figure)

A square coil of N turns (with length of each side equal L) carrying current i is placed in a uniform magnetic field →B=B0^j as shown in figure. What is the torque acting on the coil

The temperature T of one mole of an ideal gas varies with its volume V as T=−αV3+βV2, where α and β are positive constants. The maximum pressure of the gas during this process is

A body of mass 20 kg is kept on a rough horizontal surface. If μs=0.5 and an external force of F=50 N is applied on the body, find the contact force on the body. (Take g=10 m/s2)

∫(sec2x+e3x)dx is equals to

An alternating current is given by the equation i=i1 cos ωt+i2 sin ω t. The r.m.s. current is given by

A rod of mass 2 m moves vertically downward on the surface of wedge of mass as shown in the figure. Find the relation between velocity of rod and that of the wedge at any instant.

Consider the situation shown in figure. The system is released from rest and the block of mass 1.0 kg is found to have a speed 0.3 ms after it has descended through a distance of 1m. Find the coefficient of kinetic friction between the block and the table.

What will be the velocity of block A in the arrangement shown ?

In the propagation of electromagnetic waves, the angle between the direction of propagation and plane of polarization is

A dielectric slab of constant k = 3 is inserted inside gap of parallel plate capacitor of plate area L×L and separation of d at speed u. Power dissipation across resistance R is

A body of mass m kg. starts falling from a point 2R above the earth’s surface. Its kinetic energy when it has fallen to a point ‘R’ above the eart’s surface [R – Radius of earth, M – Mass of earth, G – Gravitational constant]

Find the ratio of tension T1 and T2 in the string as shown in figure if the whole system is moving with constant acceleration of 4 m/s2 under the influence of force of magnitude 220 N acting on block of mass 15 kg . Assume the coefficient of friction to be μ=1/3 and g=10 m/s2.

A bullet of mass 200 g fired with a velocity of 200 m/s, hits a block of mass 2 kg moving with a velocity of 10 m/s. After hitting the block, the bullet lodges into it. What is the velocity of the combined system? Assume that the collision is perfectly inelastic.

Calculate the force required to lift a load of 60 N, placed at a distance of 3 m from the fulcrum, if the effort is applied at a distance of 6 cm from the fulcrum.

The normals drawn on a concave mirror

A capacitor having an initial charge 0.1 C, is discharging in a simple RC circuit with the time constant 3 seconds. How much charge will remain after 6 sec?

A thin uniform rod of mass 10 kg and length 6 m is rotating about an axis perpendicular to its plane, passing through the midpoint of the rod. Find the moment of inertia of the rod about this axis.

Find the resistance of a hollow sphere whose inner surface (radius :a) and outer surface (radius b) are connected to a p.d E(ρ:resistivity)

Each condenser in the figure shown has a capacity of 3 μF. The equivalent capacity between the terminals A and B is

The eyepiece of a refracting telescope has f=9 cm. In the normal setting, seperation between objective and eyepiece is 1.8 m. Find the magnification.

Ball A of mass 10 kg moving with a velocity 6 m/s, collides with ball B of mass 50 kg which is at rest. What is the ratio of the kinetic energies of the ball A before and after the elastic collision?

Find the minimum value of coefficient of friction between the 4 kg block and the surface for the system to be at rest for the figure shown.

A stationary person observes that rain is falling vertically down at 18 km/hr. A cyclist is moving in positive x- direction on the level road, at 24 km/hr. At what angle from the horizontal should the cyclist hold his umbrella to protect himself from rain?

A parachutist drops first freely from an airplane for 10 s and then the parachute opens out. Now he descends with net retardation of 2.5 m/s2. If he bails out of the plane at a height of 2495 m and g=10 m/s2, his velocity on reaching the ground will be

In the figure shown, find the tension in the string connecting the blocks of mass 2 kg and 3 kg. Take g=10 m/s2

Two coherent sources of light can be obtained by[MH CET 2001]

The acceleration of A is as shown in the figure. If the system starts from rest, find the velocity with which the wedge hits the wall. A is constrained to move only in vertical direction.

The de Broglie wavelength of an electron moving with a velocity 0f 1.5X108 m/s is equal to that of a photon. The ratio of kinetic energy of that electron to the photon is.[IIT JEE 2004]

Two wires of the same material (Young's modulus Y) and same length L but radii R and 2R respectively are joined end to end and a weight w is suspended from the combination as shown in the figure. The elastic potential energy stored in the system is

The cut-in voltage for silicon diode is approximately

A block of mass m is located on a horizontal plane. The block acquires a horizontal velocity v0 due to friction. Find the mean power developed by the friction force during the motion of the body. The frictional cofficient is μ=0.3,m=2 kg and v0=5 m/s (Take g=10 m/s2)

Two masses m1=1 kg and m2=0.5 kg are suspended together by a massless spring of spring constant 12.5 N/m. When masses are in equilibrium, m1 is removed without disturbing the system. New amplitude of oscillation will be

Quantum nature of light is explained by which of the following phenomenon

The photoelectric effect can be understood on the basis of

If pressure at half the depth of a lake is equal to 2/3 pressure at the bottom of the lake then what is the depth of the lake

A ball is thrown from a point with a speed v0 at an angle of projection θ. From the same point and at the same instant a person starts running with a constant speed v02 to catch the ball. Will the person be able to catch the ball? If yes, what should be the angle of projection

A particle is moving with speed v=b√x along the positive x - axis. Calculate the speed of the particle at time t=τ. (Assume that the particle is at the origin at t=0).

A juggler is juggling 7 balls simultaneously. If the time gap to pass ball from one hand to the other is 2 second then find the maximum height attained by each ball.