3731 + Interview Questions in Physics Page 13 InterviewSolution

601.	A body A starts from rest with an acceleration a1 . After 2 seconds, another body B starts from rest with an acceleration a2 . If they travel equal distances in the 5th second after the start of A, then the ratio a1:a2 is equal to
Answer» A body $A$ starts from rest with an acceleration $a_{1}$ . After $2$ seconds, another body $B$ starts from rest with an acceleration $a_{2}$ . If they travel equal distances in the $5^{th} second$ after the start of $A$ , then the ratio $a_{1} : a_{2}$ is equal to

Discussion

602.	The position of the particle is given by x=2t3−4t2+5 in m. The acceleration of the particle at 5 sec is
Answer» The position of the particle is given by $x = 2 t^{3} - 4 t^{2} + 5$ in $m$ . The acceleration of the particle at $5 sec$ is

Discussion

603.	A solid sphere of uniform density and radius R applies a gravitational force of attraction equal to F1 on a particle placed at P, distance 2R from the centre O of the sphere. A spherical cavity of radius R/2 is now made in the sphere as shown in figure. The sphere with cavity now applies a gravitational force F2 on same particle placed at P. The ratio F2F1 will be
Answer» A solid sphere of uniform density and radius R applies a gravitational force of attraction equal to F₁ on a particle placed at P, distance 2R from the centre O of the sphere. A spherical cavity of radius R/2 is now made in the sphere as shown in figure. The sphere with cavity now applies a gravitational force F₂on same particle placed at P. The ratio $\frac{F_{2}}{F_{1}}$ will be

603.

A solid sphere of uniform density and radius R applies a gravitational force of attraction equal to F1 on a particle placed at P, distance 2R from the centre O of the sphere. A spherical cavity of radius R/2 is now made in the sphere as shown in figure. The sphere with cavity now applies a gravitational force F2 on same particle placed at P. The ratio F2F1 will be

Answer»

A solid sphere of uniform density and radius R applies a gravitational force of attraction equal to F₁ on a particle placed at P, distance 2R from the centre O of the sphere. A spherical cavity of radius R/2 is now made in the sphere as shown in figure. The sphere with cavity now applies a gravitational force F₂on same particle placed at P. The ratio $\frac{F_{2}}{F_{1}}$ will be

Discussion

604.	A rocket is launched by the PSLV in which fuel capacity is 500 kg. The rocket consumes 2 kg fuel in 1 s. Find the time taken by the rocket to consume 300 kg fuel.
Answer» A rocket is launched by the $P S L V$ in which fuel capacity is $500 kg$ . The rocket consumes $2 kg$ fuel in $1 s$ . Find the time taken by the rocket to consume $300 kg$ fuel.

Discussion

605.	Thermal conductivity of the conductor shown in the figure is 0.92 cal/cm s∘C. Find the thermal resistance between points P and Q (in s∘C/cal).
Answer» Thermal conductivity of the conductor shown in the figure is $0.92 {cal/cm s}^{\circ} C$ . Find the thermal resistance between points $P$ and $Q$ (in $s^{\circ} C/cal$ ).

Discussion

606.	In a series circuit R = 300 Ω , L = 0.9 H, C = 2.0 μF and ω = 1000 rad/sec. The impendence of the circuit is
Answer» In a series circuit R = 300 $Ω$ , L = 0.9 H, C = 2.0 $μ$ F and $ω$ = 1000 rad/sec. The impendence of the circuit is

Discussion

607.	The velocity of water in a river is 18 km/hr at the surface. If the river is 5 m deep, find the shearing stress between the horizontal layers of water. The viscosity of water is 10−2 Poise.
Answer» The velocity of water in a river is $18 km/hr$ at the surface. If the river is $5 m$ deep, find the shearing stress between the horizontal layers of water. The viscosity of water is $10^{- 2} Poise$ .

Discussion

608.	Point masses m1 and m2 are placed at the opposite ends of a rigid rod of length L of negligible mass. The rod is to be set rotating about an axis perpendicular to it. The position of point 'P' on this rod through which the axis should pass so that the work required to set the rod rotating with angular velocity ω0 is minimum is given by
Answer» Point masses $m_{1}$ and $m_{2}$ are placed at the opposite ends of a rigid rod of length $L$ of negligible mass. The rod is to be set rotating about an axis perpendicular to it. The position of point 'P' on this rod through which the axis should pass so that the work required to set the rod rotating with angular velocity $ω_{0}$ is minimum is given by

Discussion

609.	Molybdenum is used as a target element for production of X-rays because it is
Answer» Molybdenum is used as a target element for production of X-rays because it is

Discussion

610.	Two cars are moving on two perpendicular roads towards a crossing with uniform speeds of 72 km/h and 36 km/h. If second car blows horn of frequency 280 Hz, then the frequency of horn heard by the driver of first car when the line joining the cars makes angle of 45∘ with the roads, will be (velocity of sound is 330 m/s)
Answer» Two cars are moving on two perpendicular roads towards a crossing with uniform speeds of 72 km/h and 36 km/h. If second car blows horn of frequency 280 Hz, then the frequency of horn heard by the driver of first car when the line joining the cars makes angle of $45^{\circ}$ with the roads, will be (velocity of sound is 330 m/s)

Discussion

611.	System shown in figure is in equilibrium. Find the magnitude of net change in the string tension between two masses just after, when one of the springs is cut. Mass of both the blocks is same and equal to m and spring constant of both springs is k. Report n, if answer is mg/n
Answer» System shown in figure is in equilibrium. Find the magnitude of net change in the string tension between two masses just after, when one of the springs is cut. Mass of both the blocks is same and equal to m and spring constant of both springs is k. Report n, if answer is mg/n

Discussion

612.	The work done in raising a mass of 15 gm from the ground to a table of 1m height is
Answer» The work done in raising a mass of 15 gm from the ground to a table of 1m height is

Discussion

613.	If the mass of the body A is m. Find the mass of the body B in terms of mass of the body A for the system to be in equilibrium.
Answer» If the mass of the body $A$ is $m$ . Find the mass of the body $B$ in terms of mass of the body $A$ for the system to be in equilibrium.

Discussion

614.	A body is moving in a circular path with a constant speed. It has
Answer» A body is moving in a circular path with a constant speed. It has

Discussion

615.	A string is wrapped on the surface of a solid cylinder as shown in the figure. If the cylinder is released, then find the acceleration of the centre of mass of the cylinder and the tension in the string respectively. Mass of the cylinder is M and radius is r. (No slipping occurs between any contact points)
Answer» A string is wrapped on the surface of a solid cylinder as shown in the figure. If the cylinder is released, then find the acceleration of the centre of mass of the cylinder and the tension in the string respectively. Mass of the cylinder is $M$ and radius is $r$ . (No slipping occurs between any contact points)

Discussion

616.	Satrajit had learned in electrostatics that the electric field inside a conductor is always zero. Now they are telling him that when current flows, an electric field gets set up inside a conductor which drifts the electrons, thus making the current flow. This makes no sense to him.It makes no sense to him because
Answer» Satrajit had learned in electrostatics that the electric field inside a conductor is always zero. Now they are telling him that when current flows, an electric field gets set up inside a conductor which drifts the electrons, thus making the current flow. This makes no sense to him. It makes no sense to him because

Discussion

617.	Two particles are executing SHM, one with angular frequency ω and the other with ′2ω′. Which of the following acceleration (a) vs position (x) graphs correctly represent SHM's of two particles.
Answer» Two particles are executing SHM, one with angular frequency $ω$ and the other with $^{'} 2 ω^{'}$ . Which of the following acceleration $(a)$ vs position $(x)$ graphs correctly represent SHM's of two particles.

Discussion

618.	Two wires of same diameter of the same material having the length l and 2l. If the force F is applied on each, the ratio of the work done in the two wires will be
Answer» Two wires of same diameter of the same material having the length l and 2l. If the force F is applied on each, the ratio of the work done in the two wires will be

Discussion

619.	Find the change in the volume of 1.0 litre kerosene when it is subjected to an extra pressure of 2.0 x 105 N m−2 from the following data. Density of kerosene = 800 kg m−3 and speed of sound in kerosene = 1330 m s−1.
Answer» Find the change in the volume of 1.0 litre kerosene when it is subjected to an extra pressure of 2.0 x 10 $^{5}$ N m $^{- 2}$ from the following data. Density of kerosene = 800 kg m $^{- 3}$ and speed of sound in kerosene = 1330 m s $^{- 1}$ .

Discussion

620.	When 100 volt dc is appiled across a coil, a current of 1 amp flows through it. When 100 V A.C of 50 Hz is appiled to the same coil, only 0.5 amp flows. What is the value of inductance of the coil ?
Answer» When $100$ volt dc is appiled across a coil, a current of 1 amp flows through it. When $100 V$ A.C of $50 H z$ is appiled to the same coil, only $0.5$ amp flows. What is the value of inductance of the coil ?

Discussion

621.	Two spheres made of the same substance have diameters in the ratio 1:2. Their thermal capacities are in the ratio of:
Answer» Two spheres made of the same substance have diameters in the ratio $1 : 2$ . Their thermal capacities are in the ratio of:

Discussion

622.	An object of mass m is tied to a string of length l and a variable force F is applied on it which brings the string gradually to angle θ with the vertical. Find the work done by the force F. ( Assume initial and final kinetic energy to be zero)
Answer» An object of mass $m$ is tied to a string of length $l$ and a variable force $F$ is applied on it which brings the string gradually to angle $θ$ with the vertical. Find the work done by the force $F$ . ( Assume initial and final kinetic energy to be zero)

Discussion

623.	Three uniform rods forming a triangle would have the center of mass at
Answer» Three uniform rods forming a triangle would have the center of mass at

Discussion

624.	A diffraction is obtained by using a beam of red light. What will happen if the red light is replaced by the blue light[KCET 2000; BHU 2001]
Answer» A diffraction is obtained by using a beam of red light. What will happen if the red light is replaced by the blue light [KCET 2000; BHU 2001]

624.

A diffraction is obtained by using a beam of red light. What will happen if the red light is replaced by the blue light[KCET 2000; BHU 2001]

Answer»

A diffraction is obtained by using a beam of red light. What will happen if the red light is replaced by the blue light

[KCET 2000; BHU 2001]

Discussion

625.	A cup of tea cools from 80∘C to 60∘C in 1 min. The ambient temperature is 30∘C. How much time will it take to cool from 60∘C to 50∘C?
Answer» A cup of tea cools from $80^{\circ} C$ to $60^{\circ} C$ in $1 min$ . The ambient temperature is $30^{\circ} C$ . How much time will it take to cool from $60^{\circ} C$ to $50^{\circ} C$ ?

Discussion

626.	Figure shows a large conducting ceiling having uniform charge density σ below which a charge particle of charge q0 and mass m is hung from point O, through a small string of length L. Calculate the minimum horizontal velocity v required for the string to become horizontal.
Answer» Figure shows a large conducting ceiling having uniform charge density $σ$ below which a charge particle of charge $q_{0}$ and mass m is hung from point O, through a small string of length $L$ . Calculate the minimum horizontal velocity v required for the string to become horizontal.

Discussion

627.	The figure shows an accelerometer, a device for measuring the horizontal acceleration of cars and airplanes. A ball is free to roll on a parabolic track described by the equation y=x2, where both x and y are in meters. A scale along the bottom is used to measure the ball's horizontal position x. The mass of ball is 470 kg. The accelerometer is free to move along the horizontal.What is the magnitude of normal reaction (in N) by track on ball if ball remains at rest at x=2√3. (Given that, sinθ=4√37), where θ is the angle made by the tangent with the horizontal at this point. Take g=10 ms−2
Answer» The figure shows an accelerometer, a device for measuring the horizontal acceleration of cars and airplanes. A ball is free to roll on a parabolic track described by the equation $y = x^{2}$ , where both $x$ and $y$ are in meters. A scale along the bottom is used to measure the ball's horizontal position $x$ . The mass of ball is $\frac{4}{70} kg$ . The accelerometer is free to move along the horizontal. What is the magnitude of normal reaction (in $N$ ) by track on ball if ball remains at rest at $x = 2 \sqrt{3}$ . (Given that, $sin θ = \frac{4 \sqrt{3}}{7}$ ), where $θ$ is the angle made by the tangent with the horizontal at this point. Take $g = 10 m s^{- 2}$

Discussion

628.	A sphere of radius 1m has an equation of the form x2+y2+z2=r2Statement 1: For its surface, only 6 distinct numbers of normal vectors are possible.Statement 2: At every point of its surface intersecting with the coordinate Axis, there will a normal vector along the direction of coordinate axis at those points.
Answer» A sphere of radius 1m has an equation of the form $x^{2} + y^{2} + z^{2} = r^{2}$ Statement 1: For its surface, only 6 distinct numbers of normal vectors are possible. Statement 2: At every point of its surface intersecting with the coordinate Axis, there will a normal vector along the direction of coordinate axis at those points.

628.

A sphere of radius 1m has an equation of the form x2+y2+z2=r2Statement 1: For its surface, only 6 distinct numbers of normal vectors are possible.Statement 2: At every point of its surface intersecting with the coordinate Axis, there will a normal vector along the direction of coordinate axis at those points.

Answer»

A sphere of radius 1m has an equation of the form $x^{2} + y^{2} + z^{2} = r^{2}$

Statement 1: For its surface, only 6 distinct numbers of normal vectors are possible.

Statement 2: At every point of its surface intersecting with the coordinate Axis, there will a normal vector along the direction of coordinate axis at those points.

Discussion

629.	The coefficient of friction between the blocks of mass m and 2m is μ=2tanθ. There is no friction between the mass 2m and inclined plane. The maximum amplitude of the two block system for which there is no relative motion between both the blocks is:
Answer» The coefficient of friction between the blocks of mass $m$ and $2 m$ is $μ = 2 tan θ$ . There is no friction between the mass $2 m$ and inclined plane. The maximum amplitude of the two block system for which there is no relative motion between both the blocks is:

Discussion

630.	In radio theraphy, X-rays are used to
Answer» In radio theraphy, X-rays are used to

Discussion

631.	A particle is moving on x-axis has potential energy U=2−20x+5x2 J along x-axis. The particle is released at x=-3. The maximum value of x will be [x is in meter and U is in joule]
Answer» A particle is moving on x-axis has potential energy $U = 2 - 20 x + 5 x^{2}$ J along x-axis. The particle is released at x=-3. The maximum value of x will be [x is in meter and U is in joule]

Discussion

632.	A force acts for 10 sec on a body of mass 100 kg after which it ceases. If the body travels 160 m in the next 8 sec, find the magnitude of the force.
Answer» A force acts for 10 sec on a body of mass $100 kg$ after which it ceases. If the body travels $160 m$ in the next 8 sec, find the magnitude of the force.

Discussion

633.	A cylindrical block of wood of mass 2 kg is floating in water with its axis vertical. It is depressed by a distance x and net force on it is given by F=kx. Then, value of k in N/m is [Use π=227]
Answer» A cylindrical block of wood of mass $2 kg$ is floating in water with its axis vertical. It is depressed by a distance $x$ and net force on it is given by $F = k x$ . Then, value of $k$ in $N/m$ is [Use $π = \frac{22}{7}$ ]

Discussion

634.

Column I represents the angle at which two mirrors are inclined and column II represents number of images formed in the arrangement. Select the option that correctly matches the number of images formed with the arrangement for an object placed asymmetrical from the mirrors. Column I Column II(a) θ=60∘(1) n=1(b) θ=40∘(2) n=3(c) θ=90∘(3) n=5(d) θ=180∘(4) n=9

Answer»

Column I represents the angle at which two mirrors are inclined and column II represents number of images formed in the arrangement. Select the option that correctly matches the number of images formed with the arrangement for an object placed asymmetrical from the mirrors.

Column I	Column II
$(a) θ = 60^{\circ}$	$(1) n = 1$
$(b) θ = 40^{\circ}$	$(2) n = 3$
$(c) θ = 90^{\circ}$	$(3) n = 5$
$(d) θ = 180^{\circ}$	$(4) n = 9$

Discussion

635.	A wind - powered generator converts wind energy into electrical energy. Assume that the generator converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. For wind speed V, the electrical power output will be proportional to
Answer» A wind - powered generator converts wind energy into electrical energy. Assume that the generator converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. For wind speed V, the electrical power output will be proportional to

Discussion

636.	Two waves propagating in a given medium are represented by the curve shown below.Find the ratio of average potential energy per unit length of wave 1 is to wave 2. All measurements are in S.I unit.
Answer» Two waves propagating in a given medium are represented by the curve shown below. Find the ratio of average potential energy per unit length of wave $1$ is to wave $2$ . All measurements are in $S.I$ unit.

Discussion

637.	A band playing music at frequency f is moving towards a wall at a speed vb. A motorist is following the band with a speed vm. If v is the speed of sound, the expression for the beat frequency heard by the motorist is
Answer» A band playing music at frequency f is moving towards a wall at a speed $v_{b}$ . A motorist is following the band with a speed $v_{m}$ . If v is the speed of sound, the expression for the beat frequency heard by the motorist is

Discussion

638.	The figure here shows five paths traversed by a gas on a P-V diagram. Rank the paths according to the change in internal energy of the gas, greatest first.
Answer» The figure here shows five paths traversed by a gas on a P-V diagram. Rank the paths according to the change in internal energy of the gas, greatest first.

638.

The figure here shows five paths traversed by a gas on a P-V diagram. Rank the paths according to the change in internal energy of the gas, greatest first.

Answer»

The figure here shows five paths traversed by a gas on a P-V diagram. Rank the paths according to the change in internal energy of the gas, greatest first.

Discussion

639.	The initial volume of water is 2000 cm3. Determine the change in volume of the water when external pressure is changed from 105 Nm−2 to 106 Nm−2.[Take compressibility of water as 60×10−11 m2/N]
Answer» The initial volume of water is $2000 {cm}^{3}$ . Determine the change in volume of the water when external pressure is changed from $10^{5} {Nm}^{- 2}$ to $10^{6} {Nm}^{- 2}$ . [Take compressibility of water as $60 \times 10^{- 11} m^{2} / N$ ]

Discussion

640.	A man walks on a straight road from his home to a market 2.5 km away with a speed of 5 km/h. Finding the market closed, he instantly turns and walks back home with a speed of 7.5 km/h. The average speed of the man over the interval of time 0 to 40 minutes, is equal to
Answer» A man walks on a straight road from his home to a market $2.5 k m$ away with a speed of $5 k m / h$ . Finding the market closed, he instantly turns and walks back home with a speed of $7.5 k m / h$ . The average speed of the man over the interval of time $0$ to $40$ minutes, is equal to

Discussion

641.	Which of the following is the reason of rainbow formation?
Answer» Which of the following is the reason of rainbow formation?

Discussion

642.	Find the radius of gyration of a uniform circular disc of radius R=1 m and mass M=2 kg about its axis passing through the edge and normal to the disc as shown in figure.
Answer» Find the radius of gyration of a uniform circular disc of radius $R = 1 m$ and mass $M = 2 kg$ about its axis passing through the edge and normal to the disc as shown in figure.

Discussion

643.	The image is inverted when:
Answer» The image is inverted when:

Discussion

644.	Three equal objects of mass M each are placed on a table at points (0,0),(6,0) and (0,6) respectively . If another object of mass 2M is placed at point (2,7), the displacement of COM is
Answer» Three equal objects of mass $M$ each are placed on a table at points $(0, 0), (6, 0)$ and $(0, 6)$ respectively . If another object of mass $2 M$ is placed at point $(2, 7)$ , the displacement of $C O M$ is

Discussion

645.	A particle moves along the x−axis in such a way that its x− coordinates varies with time as x=1–2t+3t2. What will be its initial velocity?
Answer» A particle moves along the $x -$ axis in such a way that its $x -$ coordinates varies with time as $x = 1 - 2 t + 3 t^{2}$ . What will be its initial velocity?

Discussion

646.	Unpolarized light with an intensity of I0=16Wm2 is incident on a pair of polarizers. The first polarizer has its transmission axis aligned at 50∘ from the vertical. The second polarizer has its transmission axis aligned at 20∘ from the vertical.What is the intensity of the light when it emerges from the first polarizer?
Answer» Unpolarized light with an intensity of $I_{0} = 16 \frac{W}{m^{2}}$ is incident on a pair of polarizers. The first polarizer has its transmission axis aligned at $50^{\circ}$ from the vertical. The second polarizer has its transmission axis aligned at $20^{\circ}$ from the vertical. What is the intensity of the light when it emerges from the first polarizer?

Discussion

647.	An object M is placed at a distance of 3 m from a mirror kept at some height with its lower end at 2 m from ground as shown in the figure. There is a person at a distance of 4 m from the object. The ratio of minimum eye level and maximum eye level of the person required to see the image of the object M will be :
Answer» An object $M$ is placed at a distance of $3 m$ from a mirror kept at some height with its lower end at $2 m$ from ground as shown in the figure. There is a person at a distance of $4 m$ from the object. The ratio of minimum eye level and maximum eye level of the person required to see the image of the object $M$ will be :

Discussion

648.	A carnival merry-go-round rotates about a vertical axis at a constant rate. A man standing on the edge has a constant speed of 3 m/s and a centripetal acceleration →a of magnitude 2 m/s2. Position vector →r locates him relative to the rotation axis.What is the magnitude of →r ? What is the direction of →r when →a is directed due east?
Answer» A carnival merry-go-round rotates about a vertical axis at a constant rate. A man standing on the edge has a constant speed of 3 m/s and a centripetal acceleration $\to a$ of magnitude 2 m/s². Position vector $\to r$ locates him relative to the rotation axis. What is the magnitude of $\to r$ ? What is the direction of $\to r$ when $\to a$ is directed due east?

648.

A carnival merry-go-round rotates about a vertical axis at a constant rate. A man standing on the edge has a constant speed of 3 m/s and a centripetal acceleration →a of magnitude 2 m/s2. Position vector →r locates him relative to the rotation axis.What is the magnitude of →r ? What is the direction of →r when →a is directed due east?

Answer»

A carnival merry-go-round rotates about a vertical axis at a constant rate. A man standing on the edge has a constant speed of 3 m/s and a centripetal acceleration $\to a$ of magnitude 2 m/s². Position vector $\to r$ locates him relative to the rotation axis.

What is the magnitude of $\to r$ ? What is the direction of $\to r$ when $\to a$ is directed due east?

Discussion

649.	In the arrangement shown in figure, mA=4 kg and mB=1 kg. The system is released from rest and block B is found to have a speed of 0.3 m/s after it has descended through a distance of 1 m. Find the coefficient of friction between the block and the table. Neglect friction elsewhere. (Take g=10 m/s2).
Answer» In the arrangement shown in figure, $m_{A} = 4 kg$ and $m_{B} = 1 kg$ . The system is released from rest and block $B$ is found to have a speed of $0.3 m/s$ after it has descended through a distance of $1 m$ . Find the coefficient of friction between the block and the table. Neglect friction elsewhere. (Take $g = 10 {m/s}^{2}$ ).

Discussion

650.

A solid sphere of uniform density and radius 4 units is located with its centre at the origin O of coordinates. Two spheres of equal radii 1 unit with their centres at A(- 2, 0, 0) and B(2, 0, 0) respectively are taken out of the solid leaving behind spherical cavities as shown in figure. Then,

Answer»

A solid sphere of uniform density and radius 4 units is located with its centre at the origin O of coordinates. Two spheres of equal radii 1 unit with their centres at A(- 2, 0, 0) and B(2, 0, 0) respectively are taken out of the solid leaving behind spherical cavities as shown in figure. Then,

Discussion

Explore topic-wise InterviewSolutions in .

A body A starts from rest with an acceleration a1 . After 2 seconds, another body B starts from rest with an acceleration a2 . If they travel equal distances in the 5th second after the start of A, then the ratio a1:a2 is equal to

The position of the particle is given by x=2t3−4t2+5 in m. The acceleration of the particle at 5 sec is

A rocket is launched by the PSLV in which fuel capacity is 500 kg. The rocket consumes 2 kg fuel in 1 s. Find the time taken by the rocket to consume 300 kg fuel.

Thermal conductivity of the conductor shown in the figure is 0.92 cal/cm s∘C. Find the thermal resistance between points P and Q (in s∘C/cal).

In a series circuit R = 300 Ω , L = 0.9 H, C = 2.0 μF and ω = 1000 rad/sec. The impendence of the circuit is

The velocity of water in a river is 18 km/hr at the surface. If the river is 5 m deep, find the shearing stress between the horizontal layers of water. The viscosity of water is 10−2 Poise.

Molybdenum is used as a target element for production of X-rays because it is

System shown in figure is in equilibrium. Find the magnitude of net change in the string tension between two masses just after, when one of the springs is cut. Mass of both the blocks is same and equal to m and spring constant of both springs is k. Report n, if answer is mg/n

The work done in raising a mass of 15 gm from the ground to a table of 1m height is

If the mass of the body A is m. Find the mass of the body B in terms of mass of the body A for the system to be in equilibrium.

A body is moving in a circular path with a constant speed. It has

Two particles are executing SHM, one with angular frequency ω and the other with ′2ω′. Which of the following acceleration (a) vs position (x) graphs correctly represent SHM's of two particles.

Two wires of same diameter of the same material having the length l and 2l. If the force F is applied on each, the ratio of the work done in the two wires will be

Find the change in the volume of 1.0 litre kerosene when it is subjected to an extra pressure of 2.0 x 105 N m−2 from the following data. Density of kerosene = 800 kg m−3 and speed of sound in kerosene = 1330 m s−1.

When 100 volt dc is appiled across a coil, a current of 1 amp flows through it. When 100 V A.C of 50 Hz is appiled to the same coil, only 0.5 amp flows. What is the value of inductance of the coil ?

Two spheres made of the same substance have diameters in the ratio 1:2. Their thermal capacities are in the ratio of:

An object of mass m is tied to a string of length l and a variable force F is applied on it which brings the string gradually to angle θ with the vertical. Find the work done by the force F. ( Assume initial and final kinetic energy to be zero)

Three uniform rods forming a triangle would have the center of mass at

A diffraction is obtained by using a beam of red light. What will happen if the red light is replaced by the blue light[KCET 2000; BHU 2001]

A cup of tea cools from 80∘C to 60∘C in 1 min. The ambient temperature is 30∘C. How much time will it take to cool from 60∘C to 50∘C?

Figure shows a large conducting ceiling having uniform charge density σ below which a charge particle of charge q0 and mass m is hung from point O, through a small string of length L. Calculate the minimum horizontal velocity v required for the string to become horizontal.

The coefficient of friction between the blocks of mass m and 2m is μ=2tanθ. There is no friction between the mass 2m and inclined plane. The maximum amplitude of the two block system for which there is no relative motion between both the blocks is:

In radio theraphy, X-rays are used to

A particle is moving on x-axis has potential energy U=2−20x+5x2 J along x-axis. The particle is released at x=-3. The maximum value of x will be [x is in meter and U is in joule]

A force acts for 10 sec on a body of mass 100 kg after which it ceases. If the body travels 160 m in the next 8 sec, find the magnitude of the force.

A cylindrical block of wood of mass 2 kg is floating in water with its axis vertical. It is depressed by a distance x and net force on it is given by F=kx. Then, value of k in N/m is [Use π=227]

A wind - powered generator converts wind energy into electrical energy. Assume that the generator converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. For wind speed V, the electrical power output will be proportional to

Two waves propagating in a given medium are represented by the curve shown below.Find the ratio of average potential energy per unit length of wave 1 is to wave 2. All measurements are in S.I unit.

A band playing music at frequency f is moving towards a wall at a speed vb. A motorist is following the band with a speed vm. If v is the speed of sound, the expression for the beat frequency heard by the motorist is

The figure here shows five paths traversed by a gas on a P-V diagram. Rank the paths according to the change in internal energy of the gas, greatest first.

The initial volume of water is 2000 cm3. Determine the change in volume of the water when external pressure is changed from 105 Nm−2 to 106 Nm−2.[Take compressibility of water as 60×10−11 m2/N]

A man walks on a straight road from his home to a market 2.5 km away with a speed of 5 km/h. Finding the market closed, he instantly turns and walks back home with a speed of 7.5 km/h. The average speed of the man over the interval of time 0 to 40 minutes, is equal to

Which of the following is the reason of rainbow formation?

Find the radius of gyration of a uniform circular disc of radius R=1 m and mass M=2 kg about its axis passing through the edge and normal to the disc as shown in figure.

The image is inverted when:

Three equal objects of mass M each are placed on a table at points (0,0),(6,0) and (0,6) respectively . If another object of mass 2M is placed at point (2,7), the displacement of COM is

A particle moves along the x−axis in such a way that its x− coordinates varies with time as x=1–2t+3t2. What will be its initial velocity?

In the arrangement shown in figure, mA=4 kg and mB=1 kg. The system is released from rest and block B is found to have a speed of 0.3 m/s after it has descended through a distance of 1 m. Find the coefficient of friction between the block and the table. Neglect friction elsewhere. (Take g=10 m/s2).

A solid sphere of uniform density and radius 4 units is located with its centre at the origin O of coordinates. Two spheres of equal radii 1 unit with their centres at A(- 2, 0, 0) and B(2, 0, 0) respectively are taken out of the solid leaving behind spherical cavities as shown in figure. Then,