50278 + Interview Questions in Physics Page 71 InterviewSolution

3501.	A narrow sound pulse (for example, a short pip by a whistle) is sent across a medium. (a) Does the pulse have a definite (i) frequency, (ii) wavelength, (iii) speed of propagation? (b) If the pulse rate is 1 after every 20 s, (that is the whistle is blown for a split of second after every 20 s), is the frequency of the note produced by the whistle equal to 1/20 or 0.05 Hz ?
Answer» A narrow sound pulse (for example, a short pip by a whistle) is sent across a medium. (a) Does the pulse have a definite (i) frequency, (ii) wavelength, (iii) speed of propagation? (b) If the pulse rate is 1 after every 20 s, (that is the whistle is blown for a split of second after every 20 s), is the frequency of the note produced by the whistle equal to 1/20 or 0.05 Hz ?

Discussion

3502.	Rainis falling vertically with a speed of 30 ms–1.A woman rides a bicycle with a speed of 10 m s–1in the north to south direction. What is the direction in which sheshould hold her umbrella?
Answer» Rain is falling vertically with a speed of 30 m s^–1. A woman rides a bicycle with a speed of 10 m s^–1 in the north to south direction. What is the direction in which she should hold her umbrella?

Discussion

3503.	How to find instant direction of magnetic field using Fleming right hand rule
Answer» How to find instant direction of magnetic field using Fleming right hand rule

Discussion

3504.	Consider a body, shown in figure, consisting of two identical balls, each of mass 2 kg connected by a light rigid rod. If an impulse, J=20 kg - m/s is imparted to the body at one of its end, then angular velocity will be (in rad/s)
Answer» Consider a body, shown in figure, consisting of two identical balls, each of mass $2 kg$ connected by a light rigid rod. If an impulse, $J = 20 kg - m/s$ is imparted to the body at one of its end, then angular velocity will be $(in rad/s)$

Discussion

3505.	Water enters through end A with speed v1 and leaves through end B with speed v2 of a cylindrical tube AB. The tube is always completely filled with water. In case I tube is horizontal and in case II it is vertical with end A upwards and in case III it is vertical with end B upwards. We have v1 = v2 for
Answer» Water enters through end A with speed $v_{1}$ and leaves through end B with speed $v_{2}$ of a cylindrical tube AB. The tube is always completely filled with water. In case I tube is horizontal and in case II it is vertical with end A upwards and in case III it is vertical with end B upwards. We have $v_{1}$ = $v_{2}$ for

Discussion

3506.	An open pipe of sufficient length is dipping in water with a speed v vertically. If at any instant l is length of tube above water. Then the rate at which fundamental frequency of pipe changes, is (speed of sound = c)
Answer» An open pipe of sufficient length is dipping in water with a speed v vertically. If at any instant l is length of tube above water. Then the rate at which fundamental frequency of pipe changes, is (speed of sound = c)

3506.

An open pipe of sufficient length is dipping in water with a speed v vertically. If at any instant l is length of tube above water. Then the rate at which fundamental frequency of pipe changes, is (speed of sound = c)

Answer»

An open pipe of sufficient length is dipping in water with a speed v vertically. If at any instant l is length of tube above water. Then the rate at which fundamental frequency of pipe changes, is
(speed of sound = c)

Discussion

3507.	In a doubly reinforced concrete section of effective depth 500 mm, the neutral axis is at 200 mm above tensile Reinforcement. The compression steel is placed at 50 mm below the compressive edge. If the compressive stress in the extreme concrete fibre is 5N/mm2 then the stress in compressive steel is______N/mm2 [upto 2 decimal place] . [Take m = 13]54.17
Answer» In a doubly reinforced concrete section of effective depth 500 mm, the neutral axis is at 200 mm above tensile Reinforcement. The compression steel is placed at 50 mm below the compressive edge. If the compressive stress in the extreme concrete fibre is $5 N / m m^{2}$ then the stress in compressive steel is______ $N / m m^{2}$ [upto 2 decimal place] . [Take m = 13] 54.17

Discussion

3508.	A solid metallic sphere of radius R havingcharge +3Q is surrounded by a hollow spherical shell ofradius 2R and having a charge- Find distribution of charge if inner sphere is earthedinner sphere and shell are connected by a metallicwire.
Answer» A solid metallic sphere of radius R havingcharge +3Q is surrounded by a hollow spherical shell ofradius 2R and having a charge- Find distribution of charge if inner sphere is earthedinner sphere and shell are connected by a metallicwire.

Discussion

3509.	What is interference?
Answer» What is interference?

Discussion

3510.	If a=(3t2+2t+1) m/s2 is the expression according to which the acceleration of a particle moving along a straight line varies, then the change in velocity after 3 seconds of its start is
Answer» If $a = (3 t^{2} + 2 t + 1) m / s^{2}$ is the expression according to which the acceleration of a particle moving along a straight line varies, then the change in velocity after 3 seconds of its start is

Discussion

3511.	A force →F=−k(y^i+x^j) (where k is a positive constant) acts on a particle moving in the x−y plane. Starting from the origin, the particle is taken along the positive x−axis to the point (a,0) and then parallel to the y−axis to point (a,a). Then, total work done by the force is
Answer» A force $\to F = - k (y^i + x^j)$ (where $k$ is a positive constant) acts on a particle moving in the $x - y$ plane. Starting from the origin, the particle is taken along the positive $x -$ axis to the point $(a, 0)$ and then parallel to the $y -$ axis to point $(a, a)$ . Then, total work done by the force is

Discussion

3512.	A laser projects light at a mirror. The mirror reflects the light as shown. The angle r is equal to _____ degree.35
Answer» A laser projects light at a mirror. The mirror reflects the light as shown. The angle r is equal to _____ degree. 35

Discussion

3513.	How many hours would make a day if the earth were rotating at such a high speed that the weight of a body on the equator were zero (Take radius of Earth, R=6400 km and Acceleration due to gravity, g=10 ms−2).
Answer» How many hours would make a day if the earth were rotating at such a high speed that the weight of a body on the equator were zero (Take radius of Earth, $R = 6400 km$ and Acceleration due to gravity, $g = 10 {ms}^{- 2}$ ).

Discussion

3514.	Consider a small positive charge q and mass m placed as shown, between two positive charges Q (fixed) each. For a small push given to q as shown, find the time period of simple harmonic oscillations.
Answer» Consider a small positive charge $q$ and mass $m$ placed as shown, between two positive charges $Q$ (fixed) each. For a small push given to $q$ as shown, find the time period of simple harmonic oscillations.

Discussion

3515.	10.Two circular loops A and B of radii Ra and Rb respectively are made from the same uniform wire.The ratio of their moments of inertia about axes passing through their centres and perpendicular to their planes is IB/IA =8,then (Rb/Ra)=
Answer» 10.Two circular loops A and B of radii Ra and Rb respectively are made from the same uniform wire.The ratio of their moments of inertia about axes passing through their centres and perpendicular to their planes is IB/IA =8,then (Rb/Ra)=

Discussion

3516.	In the figure given below, there are two blocks A and B of weight 20 N and 100 N respectively. These are being pressed against a wall by an external force F as shown in figure. If the coefficient of static friction between the blocks is 0.1 and between block B and the wall is 0.15, then the frictional force applied by the wall on block B will be
Answer» In the figure given below, there are two blocks A and B of weight $20 N$ and $100 N$ respectively. These are being pressed against a wall by an external force $F$ as shown in figure. If the coefficient of static friction between the blocks is $0.1$ and between block B and the wall is $0.15$ , then the frictional force applied by the wall on block B will be

Discussion

3517.	Two infinite plane parallel sheets separated by a distance b have equal and opposite uniform charge densities sigma. Electric field at a point between the sheets is
Answer» Two infinite plane parallel sheets separated by a distance b have equal and opposite uniform charge densities sigma. Electric field at a point between the sheets is

Discussion

3518.	V = x^2 + xWhat is the acceleration?
Answer» V = x^2 + x What is the acceleration?

Discussion

3519.	A conducting sphere of Radius R has a total charge of Q on it. the electric potential at a point at a distance r from the centre varies as(ra) r0(r power0)b) 1/rc) 1/r2(r square)d) 1/r*3 ( r cube)
Answer» A conducting sphere of Radius R has a total charge of Q on it. the electric potential at a point at a distance r from the centre varies as(r a) r0(r power0) b) 1/r c) 1/r2(r square) d) 1/r*3 ( r cube)

Discussion

3520.	Figure shows a capillary tube of radius r dipped into water. The atmospheric pressure is P0 and the capillary rise of water is h. s is the surface tension for water-glass. Which of the following graphs may represent the relation between the capillary rise h and the radius r of the capillary?
Answer» Figure shows a capillary tube of radius $r$ dipped into water. The atmospheric pressure is $P_{0}$ and the capillary rise of water is $h$ . $s$ is the surface tension for water-glass. Which of the following graphs may represent the relation between the capillary rise $h$ and the radius $r$ of the capillary?

Discussion

3521.	A car is moving in a circular horizontal track of radius 10 m with a constant speed of 10 ms−1. A plumb bob is suspended from the roof of the car by a string of length 1 m. The angle made by the string with the vertical is (g=10 ms−2)
Answer» A car is moving in a circular horizontal track of radius $10 m$ with a constant speed of $10 {ms}^{- 1}$ . A plumb bob is suspended from the roof of the car by a string of length $1 m$ . The angle made by the string with the vertical is $(g = 10 {ms}^{- 2})$

Discussion

3522.	A 200 V shunt motor takes 10 A when running on no load. At higher loads the brush drop is 2 V and at light loads it is negligible. The stray load loss at a line current of 100 A is 50% of no load loss. If armature and field resistance is 0.2 Ω and 100 Ω respectively, then the power loss in the motor is ____kW5.1
Answer» A 200 V shunt motor takes 10 A when running on no load. At higher loads the brush drop is 2 V and at light loads it is negligible. The stray load loss at a line current of 100 A is 50% of no load loss. If armature and field resistance is 0.2 $Ω$ and 100 $Ω$ respectively, then the power loss in the motor is ____kW 5.1

Discussion

3523.	A solid sphere is kept on a rough horizontal surface. A horizontal force ′F′ is applied at centre. Calculate the acceleration of the sphere.
Answer» A solid sphere is kept on a rough horizontal surface. A horizontal force $^{'} F^{'}$ is applied at centre. Calculate the acceleration of the sphere.

Discussion

3524.	what is wave front and huygen's principle?
Answer» what is wave front and huygen's principle?

Discussion

3525.	The thickness of a sheet is reduced by rolling (without any change in width) using 600 mm diameter rolls. Neglect elastic deflection of the rolls and assume that the coefficient of friction at the roll-workpiece interface is 0.05. The sheet enters the rotating rolls unaided. If the initial sheet thickness is 2 mm, the minimum possible final thickness that can be produced by this process in a single pass is____mm(round off to two decimal places).1.25
Answer» The thickness of a sheet is reduced by rolling (without any change in width) using 600 mm diameter rolls. Neglect elastic deflection of the rolls and assume that the coefficient of friction at the roll-workpiece interface is 0.05. The sheet enters the rotating rolls unaided. If the initial sheet thickness is 2 mm, the minimum possible final thickness that can be produced by this process in a single pass is____mm(round off to two decimal places). 1.25

Discussion

3526.	Electric charge Q Q -2Q respectively are placed at three corners of an equilateral triangle of side a . Magnitude of the electric dipole moment of the system is
Answer» Electric charge Q Q -2Q respectively are placed at three corners of an equilateral triangle of side a . Magnitude of the electric dipole moment of the system is

Discussion

3527.	A ball of mass M moving with speed v collides perfectly inelastically with another ball of mass m at rest.The magnitude of impulse imparted to the first ball is
Answer» A ball of mass M moving with speed v collides perfectly inelastically with another ball of mass m at rest.The magnitude of impulse imparted to the first ball is

Discussion

3528.	A scooterist is approaching a circular turn of radius 80 m. He reduced his speed from 27 kmh−1 at constant rate of 0.5 ms−2. Find net acceleration and angle made by it wrt tangential deceleration
Answer» A scooterist is approaching a circular turn of radius $80 m$ . He reduced his speed from $27 {kmh}^{- 1}$ at constant rate of ${0.5 ms}^{- 2}$ . Find net acceleration and angle made by it wrt tangential deceleration

Discussion

3529.	A scooter going due east at 10ms−1 turns right through an angle of 90°. If the speed of the scooter remains unchanged in taking turn, the change is the velocity of the scooter is
Answer» A scooter going due east at $10 m s^{- 1}$ turns right through an angle of 90°. If the speed of the scooter remains unchanged in taking turn, the change is the velocity of the scooter is

Discussion

3530.	A cylinder of mass 100 kg is immersed in the water. It weighs 80 kg in the water. If the area of cross-section is 8 m2, then find out the length of cylinder.Density of water, ρw=1000 kg m−3Acceleration due to gravity, g=10 m s−2
Answer» A cylinder of mass $100 k g$ is immersed in the water. It weighs $80 k g$ in the water. If the area of cross-section is $8 m^{2}$ , then find out the length of cylinder. Density of water, $ρ_{w} = 1000 k g m^{- 3}$ Acceleration due to gravity, $g = 10 m s^{- 2}$

Discussion

3531.	The acceleration of the particle is given by a=2t−4 in m/s2. The displacement of the particle as a function of time is
Answer» The acceleration of the particle is given by $a = 2 t - 4$ in $m / s^{2}$ . The displacement of the particle as a function of time is

Discussion

3532.	An experimental setup for verification of photoelectric effect is shown in the diagram. The voltage across the electrodes is measured with the help of an ideal voltmeter, and it can be varied by moving jockey J on the potentiometer wire. The battery used in potentiometric circuit is of 20 V and its internal resistance is 2 Ω. The resistance of 100 cm long potentiometer wire is 8 Ω.The photo current is measured with the help of an ideal ammeter.The wavelength of various colours is as follows:Violet:4000 ˚A−5000 ˚ABlue:4500 ˚A−5000 ˚AGreen:5000 ˚A−5500 ˚AYellow:5500 ˚A−6000 ˚AOrange:6000 ˚A−6500 ˚ARed:6500 ˚A−7000 ˚AIt is found that the ammeter current remains unchanged (2 μA) even when the jockey is moved from the end P to the middle point of the potentiometer wire. Assuming one photon ejects one electron and the power of the light incident is 4×10−6 W, the colour of the incident light is:
Answer» An experimental setup for verification of photoelectric effect is shown in the diagram. The voltage across the electrodes is measured with the help of an ideal voltmeter, and it can be varied by moving jockey $J$ on the potentiometer wire. The battery used in potentiometric circuit is of $20 V$ and its internal resistance is $2 Ω$ . The resistance of $100 cm$ long potentiometer wire is $8 Ω$ . The photo current is measured with the help of an ideal ammeter. The wavelength of various colours is as follows: $Violet : 4000 ˚ A - 5000 ˚ A$ $Blue : 4500 ˚ A - 5000 ˚ A$ $Green : 5000 ˚ A - 5500 ˚ A$ $Yellow : 5500 ˚ A - 6000 ˚ A$ $Orange : 6000 ˚ A - 6500 ˚ A$ $Red : 6500 ˚ A - 7000 ˚ A$ It is found that the ammeter current remains unchanged $(2 μ A)$ even when the jockey is moved from the end $P$ to the middle point of the potentiometer wire. Assuming one photon ejects one electron and the power of the light incident is $4 \times 10^{- 6} W$ , the colour of the incident light is:

Discussion

3533.	Two blocks of masses 10 kg and 20 kg are connected by a light string passing over a frictionless pulley as shown in the figure, the angle of inclination is 30∘. If the system is released, the blocks move with an acceleration of
Answer» Two blocks of masses $10 kg$ and $20 kg$ are connected by a light string passing over a frictionless pulley as shown in the figure, the angle of inclination is $30^{\circ}$ . If the system is released, the blocks move with an acceleration of

Discussion

3534.	A long charged cylinder of linear charged density l is surroundedby a hollow co-axial conducting cylinder. What is the electric field inthe space between the two cylinders?
Answer» A long charged cylinder of linear charged density l is surroundedby a hollow co-axial conducting cylinder. What is the electric field inthe space between the two cylinders?

Discussion

3535.	Is it possible that an object is in the state of accelerated motion due to external force acting on it, but no work is being done by the force. Explain it with an example.
Answer» Is it possible that an object is in the state of accelerated motion due to external force acting on it, but no work is being done by the force. Explain it with an example.

Discussion

3536.	Torques of equal magnitude are applied to a hollow cylinder and a solid sphere, both having the same mass and radius. The cylinder is free to rotate about its standard axis of symmetry, and the sphere is free to rotate about an axis passing through its centre. Which of the two will acquire a greater angular speed after a given time.
Answer» Torques of equal magnitude are applied to a hollow cylinder and a solid sphere, both having the same mass and radius. The cylinder is free to rotate about its standard axis of symmetry, and the sphere is free to rotate about an axis passing through its centre. Which of the two will acquire a greater angular speed after a given time.

Discussion

3537.	When a wave travels in a medium, the particle displacement is given by the equation y=asin2π(bt−cx) where a, b and c are constants. The maximum particle velocity will be twice the wave velocity if
Answer» When a wave travels in a medium, the particle displacement is given by the equation $y = a sin 2 π (b t - c x)$ where $a$ , $b$ and $c$ are constants. The maximum particle velocity will be twice the wave velocity if

Discussion

3538.	Liquid is kept in a container having square cross section. It is now accelerated from left to right with an acceleration of 5 m/s2. Due to this the free surface makes some inclination with horizontal. If the length of the square cross section is 10 m, find the difference in heights of liquid at the left and the right wall. (Take g=10 m/s2)
Answer» Liquid is kept in a container having square cross section. It is now accelerated from left to right with an acceleration of $5 {m/s}^{2}$ . Due to this the free surface makes some inclination with horizontal. If the length of the square cross section is $10 m$ , find the difference in heights of liquid at the left and the right wall. (Take $g = 10 {m/s}^{2}$ )

Discussion

3539.	Calculate electric field due to charge uniformly distributed in a spherical volume
Answer» Calculate electric field due to charge uniformly distributed in a spherical volume

Discussion

3540.	Paragraph : When the rays of light after being incident on a mirror, get reflected, two situations are possible. The rays may either intersect actually or they may diverge; in which case if extrapolated they appear to intersect. A real image is formed in the former case and a real image in the later.Q If converging incident rays fall on a convex mirror:
Answer» Paragraph : When the rays of light after being incident on a mirror, get reflected, two situations are possible. The rays may either intersect actually or they may diverge; in which case if extrapolated they appear to intersect. A real image is formed in the former case and a real image in the later. Q If converging incident rays fall on a convex mirror:

3540.

Paragraph : When the rays of light after being incident on a mirror, get reflected, two situations are possible. The rays may either intersect actually or they may diverge; in which case if extrapolated they appear to intersect. A real image is formed in the former case and a real image in the later.Q If converging incident rays fall on a convex mirror:

Answer»

Paragraph : When the rays of light after being incident on a mirror, get reflected, two situations are possible. The rays may either intersect actually or they may diverge; in which case if extrapolated they appear to intersect. A real image is formed in the former case and a real image in the later.

Q If converging incident rays fall on a convex mirror:

Discussion

3541.	KF has NaCl type of structure is the age length of a unit cell has been found to be 5 37.6 p.m. the distance between ke plus minus in KF is
Answer» KF has NaCl type of structure is the age length of a unit cell has been found to be 5 37.6 p.m. the distance between ke plus minus in KF is

Discussion

3542.	A coil having 500 square loop each of side 10 cm is placed normal to the magnetic field which increases at the rate of 1T/s the induced EMF in volt is
Answer» A coil having 500 square loop each of side 10 cm is placed normal to the magnetic field which increases at the rate of 1T/s the induced EMF in volt is

Discussion

3543.	A child is standing with folded hands at the centre of a platform rotating about its central axis. The kinetic energy of the system is K. The child now stretches his hands so that the moment of inertia of the system doubles. The kinetic energy of the system now is:
Answer» A child is standing with folded hands at the centre of a platform rotating about its central axis. The kinetic energy of the system is K. The child now stretches his hands so that the moment of inertia of the system doubles. The kinetic energy of the system now is:

Discussion

3544.	If a spring of stiffness ′K′ is cut into two parts ′A′ and ′B′ of length lA=lB=2:3, then the stiffness of spring ′A′ is given by:
Answer» If a spring of stiffness $^{'} K^{'}$ is cut into two parts $^{'} A^{'}$ and $^{'} B^{'}$ of length $l_{A} = l_{B} = 2 : 3$ , then the stiffness of spring $^{'} A^{'}$ is given by:

Discussion

3545.	Why does the mass of a body change when it is in motion?
Answer» Why does the mass of a body change when it is in motion?

Discussion

3546.	A conductor of length l is placed perpendicular to a horizontal uniform magnetic field B. Suddenly a certain amount of charge is passing through it, when it is found to jump to a height h. The amount of charge that passes through the conductor is
Answer» A conductor of length $l$ is placed perpendicular to a horizontal uniform magnetic field $B .$ Suddenly a certain amount of charge is passing through it, when it is found to jump to a height $h .$ The amount of charge that passes through the conductor is

Discussion

3547.	six iden tical capacitors are connected in parallel and charged with a battery of 10V the battery is removed from it and they are now connected in series what would be the potential difference between the free plate of a capacitor
Answer» six iden tical capacitors are connected in parallel and charged with a battery of 10V the battery is removed from it and they are now connected in series what would be the potential difference between the free plate of a capacitor

Discussion

3548.	What do u mean by maGnetism & matter
Answer» What do u mean by maGnetism & matter

Discussion

3549.	How common salt is an electrolyte ?
Answer» How common salt is an electrolyte ?

Discussion

3550.	Einstein's photoelectric equation states that Ek=hv−ϕ. In this equation Ek refers to
Answer» Einstein's photoelectric equation states that $E_{k} = h v - ϕ$ . In this equation $E_{k}$ refers to

Discussion

Explore topic-wise InterviewSolutions in .

Rainis falling vertically with a speed of 30 ms–1.A woman rides a bicycle with a speed of 10 m s–1in the north to south direction. What is the direction in which sheshould hold her umbrella?

How to find instant direction of magnetic field using Fleming right hand rule

Consider a body, shown in figure, consisting of two identical balls, each of mass 2 kg connected by a light rigid rod. If an impulse, J=20 kg - m/s is imparted to the body at one of its end, then angular velocity will be (in rad/s)

An open pipe of sufficient length is dipping in water with a speed v vertically. If at any instant l is length of tube above water. Then the rate at which fundamental frequency of pipe changes, is (speed of sound = c)

A solid metallic sphere of radius R havingcharge +3Q is surrounded by a hollow spherical shell ofradius 2R and having a charge- Find distribution of charge if inner sphere is earthedinner sphere and shell are connected by a metallicwire.

What is interference?

If a=(3t2+2t+1) m/s2 is the expression according to which the acceleration of a particle moving along a straight line varies, then the change in velocity after 3 seconds of its start is

A force →F=−k(y^i+x^j) (where k is a positive constant) acts on a particle moving in the x−y plane. Starting from the origin, the particle is taken along the positive x−axis to the point (a,0) and then parallel to the y−axis to point (a,a). Then, total work done by the force is

A laser projects light at a mirror. The mirror reflects the light as shown. The angle r is equal to _____ degree.35

How many hours would make a day if the earth were rotating at such a high speed that the weight of a body on the equator were zero (Take radius of Earth, R=6400 km and Acceleration due to gravity, g=10 ms−2).

Consider a small positive charge q and mass m placed as shown, between two positive charges Q (fixed) each. For a small push given to q as shown, find the time period of simple harmonic oscillations.

10.Two circular loops A and B of radii Ra and Rb respectively are made from the same uniform wire.The ratio of their moments of inertia about axes passing through their centres and perpendicular to their planes is IB/IA =8,then (Rb/Ra)=

Two infinite plane parallel sheets separated by a distance b have equal and opposite uniform charge densities sigma. Electric field at a point between the sheets is

V = x^2 + xWhat is the acceleration?

A conducting sphere of Radius R has a total charge of Q on it. the electric potential at a point at a distance r from the centre varies as(ra) r*0(r power0)b) 1/rc) 1/r*2(r square)d) 1/r*3 ( r cube)

Figure shows a capillary tube of radius r dipped into water. The atmospheric pressure is P0 and the capillary rise of water is h. s is the surface tension for water-glass. Which of the following graphs may represent the relation between the capillary rise h and the radius r of the capillary?

A car is moving in a circular horizontal track of radius 10 m with a constant speed of 10 ms−1. A plumb bob is suspended from the roof of the car by a string of length 1 m. The angle made by the string with the vertical is (g=10 ms−2)

A solid sphere is kept on a rough horizontal surface. A horizontal force ′F′ is applied at centre. Calculate the acceleration of the sphere.

what is wave front and huygen's principle?

Electric charge Q Q -2Q respectively are placed at three corners of an equilateral triangle of side a . Magnitude of the electric dipole moment of the system is

A ball of mass M moving with speed v collides perfectly inelastically with another ball of mass m at rest.The magnitude of impulse imparted to the first ball is

A scooterist is approaching a circular turn of radius 80 m. He reduced his speed from 27 kmh−1 at constant rate of 0.5 ms−2. Find net acceleration and angle made by it wrt tangential deceleration

A scooter going due east at 10ms−1 turns right through an angle of 90°. If the speed of the scooter remains unchanged in taking turn, the change is the velocity of the scooter is

A cylinder of mass 100 kg is immersed in the water. It weighs 80 kg in the water. If the area of cross-section is 8 m2, then find out the length of cylinder.Density of water, ρw=1000 kg m−3Acceleration due to gravity, g=10 m s−2

The acceleration of the particle is given by a=2t−4 in m/s2. The displacement of the particle as a function of time is

Two blocks of masses 10 kg and 20 kg are connected by a light string passing over a frictionless pulley as shown in the figure, the angle of inclination is 30∘. If the system is released, the blocks move with an acceleration of

A long charged cylinder of linear charged density l is surroundedby a hollow co-axial conducting cylinder. What is the electric field inthe space between the two cylinders?

Is it possible that an object is in the state of accelerated motion due to external force acting on it, but no work is being done by the force. Explain it with an example.

When a wave travels in a medium, the particle displacement is given by the equation y=asin2π(bt−cx) where a, b and c are constants. The maximum particle velocity will be twice the wave velocity if

Calculate electric field due to charge uniformly distributed in a spherical volume

KF has NaCl type of structure is the age length of a unit cell has been found to be 5 37.6 p.m. the distance between ke plus minus in KF is

A coil having 500 square loop each of side 10 cm is placed normal to the magnetic field which increases at the rate of 1T/s the induced EMF in volt is

A child is standing with folded hands at the centre of a platform rotating about its central axis. The kinetic energy of the system is K. The child now stretches his hands so that the moment of inertia of the system doubles. The kinetic energy of the system now is:

If a spring of stiffness ′K′ is cut into two parts ′A′ and ′B′ of length lA=lB=2:3, then the stiffness of spring ′A′ is given by:

Why does the mass of a body change when it is in motion?

A conductor of length l is placed perpendicular to a horizontal uniform magnetic field B. Suddenly a certain amount of charge is passing through it, when it is found to jump to a height h. The amount of charge that passes through the conductor is

six iden tical capacitors are connected in parallel and charged with a battery of 10V the battery is removed from it and they are now connected in series what would be the potential difference between the free plate of a capacitor

What do u mean by maGnetism & matter

How common salt is an electrolyte ?

Einstein's photoelectric equation states that Ek=hv−ϕ. In this equation Ek refers to

A conducting sphere of Radius R has a total charge of Q on it. the electric potential at a point at a distance r from the centre varies as(ra) r0(r power0)b) 1/rc) 1/r2(r square)d) 1/r*3 ( r cube)