3731 + Interview Questions in Physics Page 14 InterviewSolution

651.	If M is the mass of water rises in a capillary tube of radius r, then what will be the mass of water which will rise in a capillary tube of same material having radius 2r?
Answer» If $M$ is the mass of water rises in a capillary tube of radius $r$ , then what will be the mass of water which will rise in a capillary tube of same material having radius $2 r$ ?

Discussion

652.	A particle is projected from the ground at an angle of θ with the horizontal with an initial speed of u. Time after which velocity vector of the projectile is perpendicular to the initial velocity is
Answer» A particle is projected from the ground at an angle of $θ$ with the horizontal with an initial speed of $u$ . Time after which velocity vector of the projectile is perpendicular to the initial velocity is

Discussion

653.	A vessel containing water has a constant acceleration of 19.6 m/s2 along horizontal direction. The free surface of water will be inclined with the horizontal at an angle of : [Take g=9.8 m/s2]
Answer» A vessel containing water has a constant acceleration of $19.6 {m/s}^{2}$ along horizontal direction. The free surface of water will be inclined with the horizontal at an angle of : [Take $g = 9.8 {m/s}^{2}$ ]

Discussion

654.	A man of mass 50 kg stands on a frame of mass 30 kg. He pulls on a light rope which passes over a pulley. The other end of the rope is attached to the frame. For the system to be in equilibrium, what force must the man exert on the rope? (Take g=10 m/s2)
Answer» A man of mass $50 kg$ stands on a frame of mass $30 kg$ . He pulls on a light rope which passes over a pulley. The other end of the rope is attached to the frame. For the system to be in equilibrium, what force must the man exert on the rope? (Take $g = 10 {m/s}^{2}$ )

Discussion

655.	The time constant of a circuit where a capacitor C=10 nF is being charged connected to a cell through a resistor of 10 Ω is.
Answer» The time constant of a circuit where a capacitor $C = 10 n F$ is being charged connected to a cell through a resistor of $10 Ω$ is.

Discussion

656.	The gravitational field due to a mass distribution is E=Kx3 in the x - direction (K is a constant).Taking the gravitational potential to be zero at infinity, its value at a distance x is:
Answer» The gravitational field due to a mass distribution is $E = \frac{K}{x^{3}}$ in the x - direction (K is a constant).Taking the gravitational potential to be zero at infinity, its value at a distance x is:

Discussion

657.	A box P and a coil Q are connected in series with an ac source of variable frequency. The emf of the source is constant at 10V. Box P contains a capacitance of 1 μF in series with a resistance of 32Ω. Coil Q has a self inductance of 4.9 mH and a resistance of 68Ω in series. The frequency is adjusted so that maximum current flows in P and Q.The voltage across P is
Answer» A box P and a coil Q are connected in series with an ac source of variable frequency. The emf of the source is constant at $10 V$ . Box P contains a capacitance of $1 μ F$ in series with a resistance of $32 Ω$ . Coil Q has a self inductance of 4.9 mH and a resistance of $68 Ω$ in series. The frequency is adjusted so that maximum current flows in P and Q. The voltage across P is

Discussion

658.	The curved part of the surface shown is semi-circular. All the surfaces are frictionless. Speed of the bigger block when the smaller block reaches the point A of the surface is:
Answer» The curved part of the surface shown is semi-circular. All the surfaces are frictionless. Speed of the bigger block when the smaller block reaches the point $A$ of the surface is:

Discussion

659.	the vector representing the body diagonal from the origin is?
Answer» the vector representing the body diagonal from the origin is?

659.

the vector representing the body diagonal from the origin is?

Answer»

the vector representing the body diagonal from the origin is?

Discussion

660.	A light and smooth pulley is attached to the ceiling of a lift moving upward with acceleration a0=2 m/s2 as shown in the figure. Two blocks of equal masses (m=3 kg) are attached to the two ends of a massless string passing over the pulley. Find the tension in the string. (Take g=10 m/s2).
Answer» A light and smooth pulley is attached to the ceiling of a lift moving upward with acceleration $a_{0} = 2 {m/s}^{2}$ as shown in the figure. Two blocks of equal masses $(m = 3 kg)$ are attached to the two ends of a massless string passing over the pulley. Find the tension in the string. (Take $g = 10 {m/s}^{2}$ ).

Discussion

661.	Four bodies of masses 2 kg,3 kg,5 kg and 8 kg respectively are placed at the four corners of a square of side 2 m. Then, position of centre of mass of the system will be:
Answer» Four bodies of masses $2 kg, 3 kg, 5 kg$ and $8 kg$ respectively are placed at the four corners of a square of side $2 m$ . Then, position of centre of mass of the system will be:

Discussion

662.	A force of 50 dynes is acted on a body of mass 5 g which is at rest for an interval of 3 seconds, then impulse is
Answer» A force of 50 dynes is acted on a body of mass 5 g which is at rest for an interval of 3 seconds, then impulse is

Discussion

663.	A 50 kg skydiver falls through the air and attains terminal velocity after some time. The drag force is a function of velocity given as Fdrag=−bv2 where the negative sign denotes that the drag force is opposite to the direction of velocity. What is the terminal velocity of the skydiver (assuming the drag constant b is 0.2 kg/m)?
Answer» A $50 kg$ skydiver falls through the air and attains terminal velocity after some time. The drag force is a function of velocity given as $F_{drag} = - b v^{2}$ where the negative sign denotes that the drag force is opposite to the direction of velocity. What is the terminal velocity of the skydiver (assuming the drag constant $b$ is $0.2 kg/m)$ ?

Discussion

664.	Three balls of masses 1 kg, 2 kg and 3 kg are attached to three strings of lengths 2 m each as shown in figure. They are rotated in a horizontal circle with angular speed ω=2 rad/s about point 'O'. Then the value of T1+T2−3T3 is
Answer» Three balls of masses $1 k g$ , $2 k g$ and $3 k g$ are attached to three strings of lengths $2 m$ each as shown in figure. They are rotated in a horizontal circle with angular speed $ω = 2 r a d / s$ about point 'O'. Then the value of $T_{1} + T_{2} - 3 T_{3}$ is

Discussion

665.	Two waves represented by y = a sin (wt − kx) and y = a cos (wt − kx) are superposed. The resultant wave will have an amplitude
Answer» Two waves represented by $y$ = $a s i n (w t - k x)$ and $y$ = $a c o s (w t - k x)$ are superposed. The resultant wave will have an amplitude

Discussion

666.	The displacement versus time curve is given below. Match the nearest option. (Assuming curves to be parabolic)Column IColumn IIi.OAa. velocity increase with time linearlyii.ABb. velocity decreases with timeiii.BCc. velocity is independent of timeiv.CDd. velocity is zero
Answer» The displacement versus time curve is given below. Match the nearest option. (Assuming curves to be parabolic) $\begin{matrix} Column I & Column II i . O A & a. velocity increase with time linearly i i . A B & b. velocity decreases with time i i i . B C & c. velocity is independent of time i v . C D & d. velocity is zero \end{matrix}$

Discussion

667.	A block is kept on a frictionless inclined surface with angle of inclination α. The incline is given an acceleration a to keep the block stationary. Then α is equal to (AIEE 2005)
Answer» A block is kept on a frictionless inclined surface with angle of inclination $α$ . The incline is given an acceleration a to keep the block stationary. Then $α$ is equal to (AIEE 2005)

667.

A block is kept on a frictionless inclined surface with angle of inclination α. The incline is given an acceleration a to keep the block stationary. Then α is equal to (AIEE 2005)

Answer»

A block is kept on a frictionless inclined surface with angle of inclination $α$ . The incline is given an acceleration a to keep the block stationary. Then $α$ is equal to

(AIEE 2005)

Discussion

668.	Derivative of f(x)=cos(x2) is
Answer» Derivative of $f (x) = cos (x^{2})$ is

Discussion

669.	Two waves, y1=2acosωt and y2=3acos(ωt+π2) meet at a point. The amplitude of the resultant wave is
Answer» Two waves, $y_{1} = 2 a cos ω t$ and $y_{2} = 3 a cos (ω t + \frac{π}{2})$ meet at a point. The amplitude of the resultant wave is

Discussion

670.	The sum of two forces acting at a point is 16 N. If the resultant force is 8 N and its direction is perpendicular to minimum force then the forces are
Answer» The sum of two forces acting at a point is 16 N. If the resultant force is 8 N and its direction is perpendicular to minimum force then the forces are

Discussion

671.	Find the Integral of the given function w.r.t xY=3x2−1√x
Answer» Find the Integral of the given function w.r.t x $Y = 3 x^{2} - \frac{1}{\sqrt{x}}$

671.

Find the Integral of the given function w.r.t xY=3x2−1√x

Answer»

Find the Integral of the given function w.r.t x

$Y = 3 x^{2} - \frac{1}{\sqrt{x}}$

Discussion

672.	The thermal conductivity of a rod depends on
Answer» The thermal conductivity of a rod depends on

Discussion

673.	A plate of mass M is moved with constant velocity v against dust particles moving with velocity u in opposite direction as shown. The density of the dust is ρ and plate area is A. Find the force F required to keep the plate moving with uniform velocity.
Answer» A plate of mass $M$ is moved with constant velocity $v$ against dust particles moving with velocity $u$ in opposite direction as shown. The density of the dust is $ρ$ and plate area is $A$ . Find the force $F$ required to keep the plate moving with uniform velocity.

Discussion

674.	A rod AB of weight W2 is placed over a sphere of weight W1 as shown in figure. If friction is absent, the number of forces to be shown on the sphere in its FBD is/are?
Answer» A rod AB of weight $W_{2}$ is placed over a sphere of weight $W_{1}$ as shown in figure. If friction is absent, the number of forces to be shown on the sphere in its $F B D$ is/are?

Discussion

675.	A sound wave of frequency 600 Hz falls normally on a perfect reflecting wall. The minimum distance from the wall at which the particles of the medium will have maximum displacement during their vibrations is [speed of sound =300 m/s]
Answer» A sound wave of frequency $600 Hz$ falls normally on a perfect reflecting wall. The minimum distance from the wall at which the particles of the medium will have maximum displacement during their vibrations is [speed of sound $= 300 m/s$ ]

Discussion

676.	A block is hanging by a string. What will be the tension in the string given the mass of the block is m?
Answer» A block is hanging by a string. What will be the tension in the string given the mass of the block is m?

Discussion

677.	The electric flux for Gaussian surface A that enclose the charged particles in free space is (given q1=−14 nC, q2=78.85 nC, q3=−56 nC)
Answer» The electric flux for Gaussian surface A that enclose the charged particles in free space is $(g i v e n q_{1} = - 14 n C, q_{2} = 78.85 n C, q_{3} = - 56 n C)$

Discussion

678.	Image formed by a convex mirror is [MP PET 1993]
Answer» Image formed by a convex mirror is [MP PET 1993]

Discussion

679.	A solid cylinder of mass (M=1 kg) and radius R=0.5 m is pivoted at its centre The axis of rotation of the cylinder is horizontal. Three small particles of mass (m=0.1 kg) are mounted along its surface as shown in figure. The system is initially at rest.The angular speed of cylinder, when it has rotated through 90∘ in anticlockwise direction.(Take g=10 m/s2)
Answer» A solid cylinder of mass ( $M = 1 kg$ ) and radius $R = 0.5 m$ is pivoted at its centre The axis of rotation of the cylinder is horizontal. Three small particles of mass ( $m = 0.1 kg$ ) are mounted along its surface as shown in figure. The system is initially at rest. The angular speed of cylinder, when it has rotated through $90^{\circ}$ in anticlockwise direction. (Take $g = 10 {m/s}^{2}$ )

Discussion

680.	In the forward bias arrangement of a PN-junction diode
Answer» In the forward bias arrangement of a PN-junction diode

Discussion

681.	A liquid of density d is pumped by a pump p from situation (i) to situation (ii) as shown in the diagram. If the cross-section of each of the vessels is a, then the work done in pumping (neglecting friction effects) is
Answer» A liquid of density d is pumped by a pump p from situation (i) to situation (ii) as shown in the diagram. If the cross-section of each of the vessels is a, then the work done in pumping (neglecting friction effects) is

681.

A liquid of density d is pumped by a pump p from situation (i) to situation (ii) as shown in the diagram. If the cross-section of each of the vessels is a, then the work done in pumping (neglecting friction effects) is

Answer»

A liquid of density d is pumped by a pump p from situation (i) to situation (ii) as shown in the diagram. If the cross-section of each of the vessels is a, then the work done in pumping (neglecting friction effects) is

Discussion

682.	Two moles of a monoatomic gas is mixed with three moles of a diatomic gas. The molar specific heat of the mixture at a constant volume is
Answer» Two moles of a monoatomic gas is mixed with three moles of a diatomic gas. The molar specific heat of the mixture at a constant volume is

Discussion

683.	A clock with a metal pendulum beating seconds keeps correct time at 0∘C. If it loses 12.5 seconds a day at 25∘C, the coefficient of linear expansion of metal of pendulum is
Answer» A clock with a metal pendulum beating seconds keeps correct time at $0^{\circ} C .$ If it loses 12.5 seconds a day at $25^{\circ} C,$ the coefficient of linear expansion of metal of pendulum is

Discussion

684.	Four charges are arranged at the corners of a square ABCD , as shown in the adjoining figure. The force on the charge kept at the centre O is
Answer» Four charges are arranged at the corners of a square ABCD , as shown in the adjoining figure. The force on the charge kept at the centre O is

Discussion

685.	Calculate the area of the triangle determined by the two vectors →A=^i−2^j+^k and →B=2^i+3^j−^k
Answer» Calculate the area of the triangle determined by the two vectors $\to A =^i - 2^j +^k$ and $\to B = 2^i + 3^j -^k$

Discussion

686.	A body released from rest slides along a frictionless track AC. Its speed at C is
Answer» A body released from rest slides along a frictionless track $A C$ . Its speed at $C$ is

Discussion

687.	Two identical blocks each of mass 10 kg are moving with a speed of 4m/s towards each other along a frictionless horizontal surface. The two blocks collide, stick together and come to rest. Consider the two blocks as a system, work done by external force is
Answer» Two identical blocks each of mass 10 kg are moving with a speed of 4m/s towards each other along a frictionless horizontal surface. The two blocks collide, stick together and come to rest. Consider the two blocks as a system, work done by external force is

Discussion

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

Discussion

689.	A particle at rest is projected from the origin moves in x−y plane with a velocity of →v=(3^i+6x^j) m/s, where ^i and ^j are unit vectors along +x and +y axis. Which of the following equations represent the equation of path followed by the particle?
Answer» A particle at rest is projected from the origin moves in $x - y$ plane with a velocity of $\to v = (3^i + 6 x^j) m/s$ , where $^i$ and $^j$ are unit vectors along $+ x$ and $+ y$ axis. Which of the following equations represent the equation of path followed by the particle?

Discussion

690.	A block of mass m is placed on a smooth wedge of inclination θ. The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block (g is the acceleration due to gravity) will be
Answer» A block of mass $m$ is placed on a smooth wedge of inclination $θ$ . The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block ( $g$ is the acceleration due to gravity) will be

Discussion

691.	The graph between u and v for a convex mirror is
Answer» The graph between u and v for a convex mirror is

691.

The graph between u and v for a convex mirror is

Answer»

The graph between u and v for a convex mirror is

Discussion

692.	A ball is thrown upwards and it returns to ground describing a parabolic path. Which of the following remains constant
Answer» A ball is thrown upwards and it returns to ground describing a parabolic path. Which of the following remains constant

Discussion

693.	A beam of hydrogen molecules is directed toward a wall, at an angle 32∘ with the normal to the wall. Each molecule in the beam has a speed of 1.0 km/s and a mass of 3.3×1024g. The beam strikes the wall over an area of 2.0 Cm2, at a rate of 4.0×1023 molecules per second. What is the beam's pressure on the wall?
Answer» A beam of hydrogen molecules is directed toward a wall, at an angle $32^{\circ}$ with the normal to the wall. Each molecule in the beam has a speed of 1.0 km/s and a mass of $3.3 \times 10^{24} g$ . The beam strikes the wall over an area of $2.0 C m^{2}$ , at a rate of $4.0 \times 10^{23}$ molecules per second. What is the beam's pressure on the wall?

Discussion

694.	Four cubes of ice at −10∘C, each of one gram, is taken out from a refrigerator and dropped into 150 g of water at 20∘C. Find the temperature of the water when thermal equilibrium is attained. Assume that no heat is lost to the outside and the water equivalent of the container is 46 g. (Specific heat capacity of water =1 cal/g∘C, specific heat capacity of ice =0.5 cal/g∘C, latent heat of fusion of ice =80 cal/g)
Answer» Four cubes of ice at $- 10^{\circ} C$ , each of one gram, is taken out from a refrigerator and dropped into $150 g$ of water at $20^{\circ} C$ . Find the temperature of the water when thermal equilibrium is attained. Assume that no heat is lost to the outside and the water equivalent of the container is $46 g$ . (Specific heat capacity of water $= 1 cal/g^{\circ} C$ , specific heat capacity of ice $= 0.5 cal/g^{\circ} C$ , latent heat of fusion of ice $= 80 cal/g$ )

Discussion

695.	Four uniform rods of different densities are connected to each other to form a square as shown in figure.Linear mass density of A, B, C and D are given as λ,2λ,2λ and 5λ. Find out the distance of COM of the square from the rod A if length of each rod is l.
Answer» Four uniform rods of different densities are connected to each other to form a square as shown in figure. Linear mass density of $A, B, C$ and $D$ are given as $λ, 2 λ, 2 λ$ and $5 λ$ . Find out the distance of $C O M$ of the square from the rod $A$ if length of each rod is $l$ .

Discussion

696.	Electrons with energy 80 keV are incident on the tungsten target of an X-ray tube. K-shell electrons of tungsten have 72.5 keV energy. X-rays emitted by the tube contain only: (IIT JEE 2000)
Answer» Electrons with energy 80 keV are incident on the tungsten target of an X-ray tube. K-shell electrons of tungsten have 72.5 keV energy. X-rays emitted by the tube contain only: (IIT JEE 2000)

Discussion

697.	The system shown in the figure consists of three springs and two rods of the same material as shown in the figure. The springs are initially relaxed and there is no friction. The temperature of the rods is increased by ΔT. The coefficient of linear expansion of the material of the rods is α. Then, energy stored in the spring 1, when the system is in equilibrium, is:
Answer» The system shown in the figure consists of three springs and two rods of the same material as shown in the figure. The springs are initially relaxed and there is no friction. The temperature of the rods is increased by $Δ T$ . The coefficient of linear expansion of the material of the rods is $α$ . Then, energy stored in the spring $1$ , when the system is in equilibrium, is:

Discussion

698.	Two bodies of masses m1 and m2 have equal kinetic energies. If p1 and p2 are their respective momentum, then ratio p1:p2 is equal to
Answer» Two bodies of masses $m_{1}$ and $m_{2}$ have equal kinetic energies. If $p_{1}$ and $p_{2}$ are their respective momentum, then ratio $p_{1} : p_{2}$ is equal to

698.

Two bodies of masses m1 and m2 have equal kinetic energies. If p1 and p2 are their respective momentum, then ratio p1:p2 is equal to

Answer»

Two bodies of masses $m_{1}$ and $m_{2}$ have equal kinetic energies. If $p_{1}$ and $p_{2}$ are their respective momentum, then ratio $p_{1} : p_{2}$ is equal to

Discussion

699.	A body falls from a height h on a horizontal surface and rebounds. Then it falls again and rebounds and so on. If the restitution coefficient is 13, the total distance covered by the body before it comes to rest is
Answer» A body falls from a height h on a horizontal surface and rebounds. Then it falls again and rebounds and so on. If the restitution coefficient is $\frac{1}{3}$ , the total distance covered by the body before it comes to rest is

Discussion

700.	A source of sound S moving with constant speed approaches a junction A. If the original frequency produced by the source is 640 Hz then for the situation shown in the figure, the apparent frequency heard by the observer at rest at O will be[speed of sound =340 m/s]
Answer» A source of sound $S$ moving with constant speed approaches a junction $A$ . If the original frequency produced by the source is $640 Hz$ then for the situation shown in the figure, the apparent frequency heard by the observer at rest at $O$ will be [speed of sound $= 340 m/s$ ]

Discussion

Explore topic-wise InterviewSolutions in .

If M is the mass of water rises in a capillary tube of radius r, then what will be the mass of water which will rise in a capillary tube of same material having radius 2r?

A particle is projected from the ground at an angle of θ with the horizontal with an initial speed of u. Time after which velocity vector of the projectile is perpendicular to the initial velocity is

A vessel containing water has a constant acceleration of 19.6 m/s2 along horizontal direction. The free surface of water will be inclined with the horizontal at an angle of : [Take g=9.8 m/s2]

A man of mass 50 kg stands on a frame of mass 30 kg. He pulls on a light rope which passes over a pulley. The other end of the rope is attached to the frame. For the system to be in equilibrium, what force must the man exert on the rope? (Take g=10 m/s2)

The time constant of a circuit where a capacitor C=10 nF is being charged connected to a cell through a resistor of 10 Ω is.

The gravitational field due to a mass distribution is E=Kx3 in the x - direction (K is a constant).Taking the gravitational potential to be zero at infinity, its value at a distance x is:

The curved part of the surface shown is semi-circular. All the surfaces are frictionless. Speed of the bigger block when the smaller block reaches the point A of the surface is:

the vector representing the body diagonal from the origin is?

A light and smooth pulley is attached to the ceiling of a lift moving upward with acceleration a0=2 m/s2 as shown in the figure. Two blocks of equal masses (m=3 kg) are attached to the two ends of a massless string passing over the pulley. Find the tension in the string. (Take g=10 m/s2).

Four bodies of masses 2 kg,3 kg,5 kg and 8 kg respectively are placed at the four corners of a square of side 2 m. Then, position of centre of mass of the system will be:

A force of 50 dynes is acted on a body of mass 5 g which is at rest for an interval of 3 seconds, then impulse is

Three balls of masses 1 kg, 2 kg and 3 kg are attached to three strings of lengths 2 m each as shown in figure. They are rotated in a horizontal circle with angular speed ω=2 rad/s about point 'O'. Then the value of T1+T2−3T3 is

Two waves represented by y = a sin (wt − kx) and y = a cos (wt − kx) are superposed. The resultant wave will have an amplitude

The displacement versus time curve is given below. Match the nearest option. (Assuming curves to be parabolic)Column IColumn IIi.OAa. velocity increase with time linearlyii.ABb. velocity decreases with timeiii.BCc. velocity is independent of timeiv.CDd. velocity is zero

A block is kept on a frictionless inclined surface with angle of inclination α. The incline is given an acceleration a to keep the block stationary. Then α is equal to (AIEE 2005)

Derivative of f(x)=cos(x2) is

Two waves, y1=2acosωt and y2=3acos(ωt+π2) meet at a point. The amplitude of the resultant wave is

The sum of two forces acting at a point is 16 N. If the resultant force is 8 N and its direction is perpendicular to minimum force then the forces are

Find the Integral of the given function w.r.t xY=3x2−1√x

The thermal conductivity of a rod depends on

A plate of mass M is moved with constant velocity v against dust particles moving with velocity u in opposite direction as shown. The density of the dust is ρ and plate area is A. Find the force F required to keep the plate moving with uniform velocity.

A rod AB of weight W2 is placed over a sphere of weight W1 as shown in figure. If friction is absent, the number of forces to be shown on the sphere in its FBD is/are?

A sound wave of frequency 600 Hz falls normally on a perfect reflecting wall. The minimum distance from the wall at which the particles of the medium will have maximum displacement during their vibrations is [speed of sound =300 m/s]

A block is hanging by a string. What will be the tension in the string given the mass of the block is m?

The electric flux for Gaussian surface A that enclose the charged particles in free space is (given q1=−14 nC, q2=78.85 nC, q3=−56 nC)

Image formed by a convex mirror is [MP PET 1993]

In the forward bias arrangement of a PN-junction diode

A liquid of density d is pumped by a pump p from situation (i) to situation (ii) as shown in the diagram. If the cross-section of each of the vessels is a, then the work done in pumping (neglecting friction effects) is

Two moles of a monoatomic gas is mixed with three moles of a diatomic gas. The molar specific heat of the mixture at a constant volume is

A clock with a metal pendulum beating seconds keeps correct time at 0∘C. If it loses 12.5 seconds a day at 25∘C, the coefficient of linear expansion of metal of pendulum is

Four charges are arranged at the corners of a square ABCD , as shown in the adjoining figure. The force on the charge kept at the centre O is

Calculate the area of the triangle determined by the two vectors →A=^i−2^j+^k and →B=2^i+3^j−^k

A body released from rest slides along a frictionless track AC. Its speed at C is

Two identical blocks each of mass 10 kg are moving with a speed of 4m/s towards each other along a frictionless horizontal surface. The two blocks collide, stick together and come to rest. Consider the two blocks as a system, work done by external force is

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

A particle at rest is projected from the origin moves in x−y plane with a velocity of →v=(3^i+6x^j) m/s, where ^i and ^j are unit vectors along +x and +y axis. Which of the following equations represent the equation of path followed by the particle?

A block of mass m is placed on a smooth wedge of inclination θ. The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block (g is the acceleration due to gravity) will be

The graph between u and v for a convex mirror is

A ball is thrown upwards and it returns to ground describing a parabolic path. Which of the following remains constant

Four uniform rods of different densities are connected to each other to form a square as shown in figure.Linear mass density of A, B, C and D are given as λ,2λ,2λ and 5λ. Find out the distance of COM of the square from the rod A if length of each rod is l.

Electrons with energy 80 keV are incident on the tungsten target of an X-ray tube. K-shell electrons of tungsten have 72.5 keV energy. X-rays emitted by the tube contain only: (IIT JEE 2000)

Two bodies of masses m1 and m2 have equal kinetic energies. If p1 and p2 are their respective momentum, then ratio p1:p2 is equal to

A body falls from a height h on a horizontal surface and rebounds. Then it falls again and rebounds and so on. If the restitution coefficient is 13, the total distance covered by the body before it comes to rest is

A source of sound S moving with constant speed approaches a junction A. If the original frequency produced by the source is 640 Hz then for the situation shown in the figure, the apparent frequency heard by the observer at rest at O will be[speed of sound =340 m/s]