50278 + Interview Questions in Physics Page 132 InterviewSolution

6551.	Three concentric metallic spherical shells of radii R, 2R, 3R are given charges Q1, Q2, Q3 respectively. It is found that the surface charge densities on the outer surfaces of the shells are equal. Then, the ratio of the charges given to the shells Q1 : Q2 : Q3 is
Answer» Three concentric metallic spherical shells of radii R, 2R, 3R are given charges Q1, Q2, Q3 respectively. It is found that the surface charge densities on the outer surfaces of the shells are equal. Then, the ratio of the charges given to the shells Q1 : Q2 : Q3 is

Discussion

6552.	If the charge of one body is doubled and the distance between the charged bodies is tripled . What is the net force between them?
Answer» If the charge of one body is doubled and the distance between the charged bodies is tripled . What is the net force between them?

Discussion

6553.	Two parallel sheets 1 and 2 carry uniform charge densities σ1 and σ2 (σ1>σ2) as shown in figure. The electric field in the region marked II is
Answer» Two parallel sheets $1$ and $2$ carry uniform charge densities $σ_{1}$ and $σ_{2}$ $(σ_{1} > σ_{2})$ as shown in figure. The electric field in the region marked $I I$ is

Discussion

6554.	Consider a parallel-plate capacitor of capacitance 10 μF with air filled in the gap between the plates. Now, one half of the space between the plates is filled with a dielectric of dielectric constant 4 as shown in the figure. The capacitance of the capacitor changes to
Answer» Consider a parallel-plate capacitor of capacitance $10 μ F$ with air filled in the gap between the plates. Now, one half of the space between the plates is filled with a dielectric of dielectric constant 4 as shown in the figure. The capacitance of the capacitor changes to

Discussion

6555.	Find the value of the trigonometric function
Answer» Find the value of the trigonometric function

Discussion

6556.	A boat is rowed perpendicular to river flow at the rate of 5 km/hr. The river flows at the rate of 2.5 km/hr. The speed of boat approximately in m/s is
Answer» A boat is rowed perpendicular to river flow at the rate of $5 km/hr$ . The river flows at the rate of $2.5 km/hr$ . The speed of boat approximately in $m/s$ is

Discussion

6557.	The temperature inside a refrigerator is T2 C and the room temperature is T1 C. The amount of heat delivered to the room for each joule of electrical energy consumed ideally will be
Answer» The temperature inside a refrigerator is T2 C and the room temperature is T1 C. The amount of heat delivered to the room for each joule of electrical energy consumed ideally will be

Discussion

6558.	The horizontal range and maximum height for a projectile is same. The angle of projectile is
Answer» The horizontal range and maximum height for a projectile is same. The angle of projectile is

Discussion

6559.	A steel wire of diameter d, area of cross-section A and length 2L is clamped firmly at two points A and B which are 2L metre apart and in the same plane. A body of mass m is hung from the middle point of wire such that the middle point sags by x lower from original position. If Young’s modulus is Y then m is given by
Answer» A steel wire of diameter d, area of cross-section A and length 2L is clamped firmly at two points A and B which are 2L metre apart and in the same plane. A body of mass m is hung from the middle point of wire such that the middle point sags by x lower from original position. If Young’s modulus is Y then m is given by

Discussion

6560.	A disc of mass M, and radius R is attached to the massless rod as shown. The period of oscillation of the pendulum is
Answer» A disc of mass M, and radius R is attached to the massless rod as shown. The period of oscillation of the pendulum is

Discussion

6561.	The power factor of the ac circuit given below is 1√2. The capacitance of the capacitor in the circuit is equal to
Answer» The power factor of the ac circuit given below is $\frac{1}{\sqrt{2}}$ . The capacitance of the capacitor in the circuit is equal to

Discussion

6562.	3.The length of metallic wire is l1 metre when the tension is 4N and l2 when the tension is 6N .Find the length when the tension is 9N and find actual length of wire .
Answer» 3.The length of metallic wire is l1 metre when the tension is 4N and l2 when the tension is 6N .Find the length when the tension is 9N and find actual length of wire .

Discussion

6563.	A wave of wavelength 2 cm and velocity 6 cm s−1 is travelling on a string and after collision with a rigid boundary, it forms a standing wave. Assuming that wave is in third mode of vibration, the equation of standing wave formed will be
Answer» A wave of wavelength $2 cm$ and velocity $6 {cm s}^{- 1}$ is travelling on a string and after collision with a rigid boundary, it forms a standing wave. Assuming that wave is in third mode of vibration, the equation of standing wave formed will be

Discussion

6564.	61.There are four charge of equal magnitude( magnitude of charge is q) on the corner of a square. Find the potential energy of the system if one of the is -q.
Answer» 61.There are four charge of equal magnitude( magnitude of charge is q) on the corner of a square. Find the potential energy of the system if one of the is -q.

Discussion

6565.	A car has to negotiate a curve of radius 200 m. By how much should the outer side of the road be raised with respect to the inner side for a speed of 72 km/h. The width of the road is 1 m. (g=10 m/s2)
Answer» A car has to negotiate a curve of radius $200 m$ . By how much should the outer side of the road be raised with respect to the inner side for a speed of $72 km/h$ . The width of the road is $1 m$ . $(g = 10 {m/s}^{2})$

Discussion

6566.	A physical quantity →S is defined as →S=(→E×→B)/μ0, where →E is electric field, →B is magnetic field and μ0 is the permeability of free space. The dimensions of →S are the same as the dimensions of which of the following quantity(ies) ?
Answer» A physical quantity $\to S$ is defined as $\to S = (\to E \times \to B) / μ_{0},$ where $\to E$ is electric field, $\to B$ is magnetic field and $μ_{0}$ is the permeability of free space. The dimensions of $\to S$ are the same as the dimensions of which of the following quantity(ies) ?

Discussion

6567.	An ion which carries +3 charge posseses magneticmoment of 4.9 B.M. and its last electronpossesses orbital angular momentum of 6hIdentify that element if highest value of n in theE.C. of that ion is 3.
Answer» An ion which carries +3 charge posseses magneticmoment of 4.9 B.M. and its last electronpossesses orbital angular momentum of 6hIdentify that element if highest value of n in theE.C. of that ion is 3.

Discussion

6568.	45.A small spherically symmetric charge q is placed at one vertex of a cube as shown in fig. The flux through the faves ABCD and HGEF are,
Answer» 45.A small spherically symmetric charge q is placed at one vertex of a cube as shown in fig. The flux through the faves ABCD and HGEF are,

Discussion

6569.	Two plane mirrors A and B are aligned parallel to each other, as shown in the figure. A light ray is incident at an angle of 30∘ at a point just at the edge of A. The plane of incidence coincides with the plane of the figure. The maximum number of times the ray undergoes reflection (including the first one) before it emerges out is
Answer» Two plane mirrors $A$ and $B$ are aligned parallel to each other, as shown in the figure. A light ray is incident at an angle of $30^{\circ}$ at a point just at the edge of $A$ . The plane of incidence coincides with the plane of the figure. The maximum number of times the ray undergoes reflection (including the first one) before it emerges out is

Discussion

6570.	The value of k>0 so that the area of the bounded region enclosed between the parabolas y=x−kx2 and y=x2k is maximum, is
Answer» The value of $k > 0$ so that the area of the bounded region enclosed between the parabolas $y = x - k x^{2}$ and $y = \frac{x^{2}}{k}$ is maximum, is

Discussion

6571.	In the figure given below, block A is of mass m and block B is of mass 2m. The spring has force constant k. All the surfaces are smooth and the system is released from rest with the spring unstretched. Maximum extension in the spring is
Answer» In the figure given below, block $A$ is of mass $m$ and block B is of mass $2 m$ . The spring has force constant $k$ . All the surfaces are smooth and the system is released from rest with the spring unstretched. Maximum extension in the spring is

Discussion

6572.	a charge 'q' is placed at the center of a cube of side 'l'. What is the electric flux passing through the two faces of the cube?
Answer» a charge 'q' is placed at the center of a cube of side 'l'. What is the electric flux passing through the two faces of the cube?

Discussion

6573.	A cube is arranged such that its length, breadth and height are along X, Y and Z directions. One of its corners is situated at the origin. Length of each side of the cube is 25 cm. The components of electric field are Ex=400 √2N/C,Ey=0 and Ez=0 respectively. Find the flux coming out of the cube at one end.
Answer» A cube is arranged such that its length, breadth and height are along X, Y and Z directions. One of its corners is situated at the origin. Length of each side of the cube is 25 cm. The components of electric field are $E_{x} = 400 \sqrt{2} N / C, E_{y} = 0 a n d E_{z} = 0$ respectively. Find the flux coming out of the cube at one end.

Discussion

6574.	Why charge is not relativistic
Answer» Why charge is not relativistic

Discussion

6575.	In the following figure force F is gradually increased from zero. Draw the graph between applied force F and tension T in the string. The coefficient of static friction between the block and the ground is μs.
Answer» In the following figure force F is gradually increased from zero. Draw the graph between applied force F and tension T in the string. The coefficient of static friction between the block and the ground is $μ_{s}$ .

6575.

In the following figure force F is gradually increased from zero. Draw the graph between applied force F and tension T in the string. The coefficient of static friction between the block and the ground is μs.

Answer»

In the following figure force F is gradually increased from zero. Draw the graph between applied force F and tension T in the string. The coefficient of static friction between the block and the ground is $μ_{s}$ .

Discussion

6576.	In a disc-type axial clutch, the frictional contact takes place within an annular region with outer and inner diameters 250 mm and 50 mm respectively. An axial force F1 is needed to transmit a torque by a new clutch. However, to transmit the same torque one needs an axial force F2 when the clutch wears out. If contact pressure remains uniform during operation of a new clutch while the wear is assumed to be uniform for an old clutch and the coefficient of friction does not change, then the ratio F1F2 is (round off to 2 decimal places)0.871
Answer» In a disc-type axial clutch, the frictional contact takes place within an annular region with outer and inner diameters 250 mm and 50 mm respectively. An axial force $F_{1}$ is needed to transmit a torque by a new clutch. However, to transmit the same torque one needs an axial force $F_{2}$ when the clutch wears out. If contact pressure remains uniform during operation of a new clutch while the wear is assumed to be uniform for an old clutch and the coefficient of friction does not change, then the ratio $\frac{F_{1}}{F_{2}}$ is (round off to 2 decimal places) 0.871

Discussion

6577.	a charged parallel plate capacitor of dis†an ce d has u energy.a slab of dielectric cons†an t(k) and thickness (d) is the introduce between the plates of the capacitor.the new energy of the system is given b a)ku b)u/k c)k^2u d)none of thes
Answer» a charged parallel plate capacitor of dis†an ce d has u energy.a slab of dielectric cons†an t(k) and thickness (d) is the introduce between the plates of the capacitor.the new energy of the system is given b a)ku b)u/k c)k^2u d)none of thes

Discussion

6578.	Newton second is unit of ? a.velocityb.angular momentumc.linear momentumd.energy
Answer» Newton second is unit of ? a.velocity b.angular momentum c.linear momentum d.energy

Discussion

6579.	The electric field →E=(20^i+30^j) N/C exists in space. If the potential at origin in taken to be zero, find the potential at P(3,2).
Answer» The electric field $\to E = (20^i + 30^j) N/C$ exists in space. If the potential at origin in taken to be zero, find the potential at $P (3, 2)$ .

Discussion

6580.	A ray of light falls on a plane mirror. When the mirror is turned clockwise about an axis along the plane of the mirror by 20∘, the incident ray gets deflected by 45∘. The original incidence angle is
Answer» A ray of light falls on a plane mirror. When the mirror is turned clockwise about an axis along the plane of the mirror by $20^{\circ}$ , the incident ray gets deflected by $45^{\circ}$ . The original incidence angle is

Discussion

6581.	Two circular coils A and B of same radius are made from wire of similar materials but the radius of wire B is twice that of A. The ratio of values of the potential difference across A and B, such that the magnetic field induction at their centre may be same, will be
Answer» Two circular coils $A$ and $B$ of same radius are made from wire of similar materials but the radius of wire $B$ is twice that of $A$ . The ratio of values of the potential difference across $A$ and $B$ , such that the magnetic field induction at their centre may be same, will be

Discussion

6582.	If one of the two electrons of a H2 molecule is removed, we get ahydrogen molecular ion H+2. In the ground state of an H+2, the twoprotons are separated by roughly 1.5 Å, and the electron is roughly1 Å from each proton. Determine the potential energy of the system.Specify your choice of the zero of potential energy.
Answer» If one of the two electrons of a H2 molecule is removed, we get ahydrogen molecular ion H+2. In the ground state of an H+2, the twoprotons are separated by roughly 1.5 Å, and the electron is roughly1 Å from each proton. Determine the potential energy of the system.Specify your choice of the zero of potential energy.

Discussion

6583.	Find the derivative of y=sin(x2−4)
Answer» Find the derivative of $y = s i n (x^{2} - 4)$

Discussion

6584.	P−V plots for two gases during adiabatic processes are shown in the figure. Plots 1 and 2 should correspond respectively to
Answer» $P - V$ plots for two gases during adiabatic processes are shown in the figure. Plots $1$ and $2$ should correspond respectively to

Discussion

6585.	If the angle of polarization for a medium is 60°, what will be critical angle?
Answer» If the angle of polarization for a medium is $60 °$ , what will be critical angle?

Discussion

6586.	Light with an energy flux of 25×104 Wm−2 falls on a perfectly reflecting surface at normal incidence. If the surface area is 15 cm2, the average force exerted on the surface is :
Answer» Light with an energy flux of $25 \times 10^{4} {Wm}^{- 2}$ falls on a perfectly reflecting surface at normal incidence. If the surface area is $15 {cm}^{2}$ , the average force exerted on the surface is :

Discussion

6587.	if the strain in a wire is not more than 1/1000 and Y = 2 * 10^11 N/m^2, Diameter of wire is 1 mm. The maximum weight hung from the wire is
Answer» if the strain in a wire is not more than 1/1000 and Y = 2 * 10^11 N/m^2, Diameter of wire is 1 mm. The maximum weight hung from the wire is

Discussion

6588.	A proton, a deuteron and an α particle having same momentum enter a uniform magnetic field at right angles to the field. The ratio of their angular momentum with respect to their corresponding centres during their motion in the magnetic field is
Answer» A proton, a deuteron and an $α$ particle having same momentum enter a uniform magnetic field at right angles to the field. The ratio of their angular momentum with respect to their corresponding centres during their motion in the magnetic field is

Discussion

6589.	37.Define electric dipole moment in terms of torque
Answer» 37.Define electric dipole moment in terms of torque

Discussion

6590.	If a gas occupies a volume of 300cc at 27 degree C and 620 mm pressure then the volume of the gas at 47 degree C and 640 mm pressure is
Answer» If a gas occupies a volume of 300cc at 27 degree C and 620 mm pressure then the volume of the gas at 47 degree C and 640 mm pressure is

Discussion

6591.	Calculate the number of turns in a toroid when the charges of 8 C flows in 1 minute through it, produce a magnetic field of 2.5×10−4 T.[Radius of the toroid is 20 cm]
Answer» Calculate the number of turns in a toroid when the charges of $8 C$ flows in $1 minute$ through it, produce a magnetic field of $2.5 \times 10^{- 4} T$ . [Radius of the toroid is $20 cm$ ]

Discussion

6592.	A system consists of two types of gas molecules A and B having the same number density 2×1025 m−3. The diameter of A and B are 10 ˙A and 5 ˙A respectively. They suffer collision at room temperature. The ratio of average distance covered by the molecule A to that of B between two successive collision is ×10−2
Answer» A system consists of two types of gas molecules $A$ and $B$ having the same number density $2 \times 10^{25} m^{- 3}$ . The diameter of $A$ and $B$ are $10 ˙ A$ and $5 ˙ A$ respectively. They suffer collision at room temperature. The ratio of average distance covered by the molecule $A$ to that of $B$ between two successive collision is $\times 10^{- 2}$

Discussion

6593.	A particle is performing SHM with an amplitude A and angular frequency ω. Find the displacement of the particle from the mean position where the speed of the particle becomes half of the maximum speed.
Answer» A particle is performing SHM with an amplitude $A$ and angular frequency $ω$ . Find the displacement of the particle from the mean position where the speed of the particle becomes half of the maximum speed.

Discussion

6594.	Two large plates are held 1.5 mm apart. An electric field of 10^7Vm^- exists between the plates with no electric field outside.What is the charge density on the plates?
Answer» Two large plates are held 1.5 mm apart. An electric field of 10^7Vm^- exists between the plates with no electric field outside.What is the charge density on the plates?

Discussion

6595.	A wheel and an axle is made to rotate about a horizontal axis with the help of a body of mass 5 kg attached to a string wound around the axle. The radius of the axle is 10 cm. The body falls vertically throught 5 m is 10 s starting from rest. The moment of inertial of the wheel and axle is (1)3.85 kg m2 (2) 4.85 kg m2 (3) 5.85 kg m2 (4) 2.85 kg m2
Answer» A wheel and an axle is made to rotate about a horizontal axis with the help of a body of mass 5 kg attached to a string wound around the axle. The radius of the axle is 10 cm. The body falls vertically throught 5 m is 10 s starting from rest. The moment of inertial of the wheel and axle is (1)3.85 kg m2 (2) 4.85 kg m2 (3) 5.85 kg m2 (4) 2.85 kg m2

Discussion

6596.	A closed hollow insulated cylinder is filled with a gas at 0∘C and also contains an insulated piston of negligible weight and negligible thickness at the middle point. The gas on one side of the piston is heated to 100∘C. If the piston moves by 5 cm, the length of the hollow cylinder is
Answer» A closed hollow insulated cylinder is filled with a gas at $0^{\circ} C$ and also contains an insulated piston of negligible weight and negligible thickness at the middle point. The gas on one side of the piston is heated to $100^{\circ} C$ . If the piston moves by $5 cm$ , the length of the hollow cylinder is

Discussion

6597.	Radiation of wavelength λ, is incident on a photocell. The fastest emitted electron has speed v. If the wavelength is changed to 3λ4, the speed of the fastest emitted electron will be :
Answer» Radiation of wavelength $λ,$ is incident on a photocell. The fastest emitted electron has speed $v$ . If the wavelength is changed to $\frac{3 λ}{4}$ , the speed of the fastest emitted electron will be :

Discussion

6598.	A nucleus of Mass M+Δm is at rest and decays into two daughter nuclei of equal mass M2 each. Speed of light is c. The speed of daughter nuclei is
Answer» A nucleus of Mass $M + Δ m$ is at rest and decays into two daughter nuclei of equal mass $\frac{M}{2}$ each. Speed of light is $c$ . The speed of daughter nuclei is

Discussion

6599.	An uncharged capacitor is fully charged with a battery . the ratio of energy stored in the capacitor to the work done by the battery in this process is
Answer» An uncharged capacitor is fully charged with a battery . the ratio of energy stored in the capacitor to the work done by the battery in this process is

Discussion

6600.	How long will it take sound waves to travel the distance between the points A and B, separated by a distance l, if the air temperature between them varies linearly from T1 to T2? The velocity of sound propagation in air is equal to v=α√TWhere α is a constant.
Answer» How long will it take sound waves to travel the distance between the points A and B, separated by a distance l, if the air temperature between them varies linearly from $T_{1}$ to $T_{2}$ ? The velocity of sound propagation in air is equal to $v = α \sqrt{T}$ Where $α$ is a constant.

Discussion

Explore topic-wise InterviewSolutions in .

Three concentric metallic spherical shells of radii R, 2R, 3R are given charges Q1, Q2, Q3 respectively. It is found that the surface charge densities on the outer surfaces of the shells are equal. Then, the ratio of the charges given to the shells Q1 : Q2 : Q3 is

If the charge of one body is doubled and the distance between the charged bodies is tripled . What is the net force between them?

Two parallel sheets 1 and 2 carry uniform charge densities σ1 and σ2 (σ1&gt;σ2) as shown in figure. The electric field in the region marked II is

Consider a parallel-plate capacitor of capacitance 10 μF with air filled in the gap between the plates. Now, one half of the space between the plates is filled with a dielectric of dielectric constant 4 as shown in the figure. The capacitance of the capacitor changes to

Find the value of the trigonometric function

A boat is rowed perpendicular to river flow at the rate of 5 km/hr. The river flows at the rate of 2.5 km/hr. The speed of boat approximately in m/s is

The temperature inside a refrigerator is T2 C and the room temperature is T1 C. The amount of heat delivered to the room for each joule of electrical energy consumed ideally will be

The horizontal range and maximum height for a projectile is same. The angle of projectile is

A disc of mass M, and radius R is attached to the massless rod as shown. The period of oscillation of the pendulum is

The power factor of the ac circuit given below is 1√2. The capacitance of the capacitor in the circuit is equal to

3.The length of metallic wire is l1 metre when the tension is 4N and l2 when the tension is 6N .Find the length when the tension is 9N and find actual length of wire .

A wave of wavelength 2 cm and velocity 6 cm s−1 is travelling on a string and after collision with a rigid boundary, it forms a standing wave. Assuming that wave is in third mode of vibration, the equation of standing wave formed will be

61.There are four charge of equal magnitude( magnitude of charge is q) on the corner of a square. Find the potential energy of the system if one of the is -q.

A car has to negotiate a curve of radius 200 m. By how much should the outer side of the road be raised with respect to the inner side for a speed of 72 km/h. The width of the road is 1 m. (g=10 m/s2)

A physical quantity →S is defined as →S=(→E×→B)/μ0, where →E is electric field, →B is magnetic field and μ0 is the permeability of free space. The dimensions of →S are the same as the dimensions of which of the following quantity(ies) ?

An ion which carries +3 charge posseses magneticmoment of 4.9 B.M. and its last electronpossesses orbital angular momentum of 6hIdentify that element if highest value of n in theE.C. of that ion is 3.

45.A small spherically symmetric charge q is placed at one vertex of a cube as shown in fig. The flux through the faves ABCD and HGEF are,

The value of k&gt;0 so that the area of the bounded region enclosed between the parabolas y=x−kx2 and y=x2k is maximum, is

In the figure given below, block A is of mass m and block B is of mass 2m. The spring has force constant k. All the surfaces are smooth and the system is released from rest with the spring unstretched. Maximum extension in the spring is

a charge 'q' is placed at the center of a cube of side 'l'. What is the electric flux passing through the two faces of the cube?

Why charge is not relativistic

In the following figure force F is gradually increased from zero. Draw the graph between applied force F and tension T in the string. The coefficient of static friction between the block and the ground is μs.

a charged parallel plate capacitor of dis†an ce d has u energy.a slab of dielectric cons†an t(k) and thickness (d) is the introduce between the plates of the capacitor.the new energy of the system is given b a)ku b)u/k c)k^2u d)none of thes

Newton second is unit of ? a.velocityb.angular momentumc.linear momentumd.energy

The electric field →E=(20^i+30^j) N/C exists in space. If the potential at origin in taken to be zero, find the potential at P(3,2).

A ray of light falls on a plane mirror. When the mirror is turned clockwise about an axis along the plane of the mirror by 20∘, the incident ray gets deflected by 45∘. The original incidence angle is

Two circular coils A and B of same radius are made from wire of similar materials but the radius of wire B is twice that of A. The ratio of values of the potential difference across A and B, such that the magnetic field induction at their centre may be same, will be

Find the derivative of y=sin(x2−4)

P−V plots for two gases during adiabatic processes are shown in the figure. Plots 1 and 2 should correspond respectively to

If the angle of polarization for a medium is 60°, what will be critical angle?

Light with an energy flux of 25×104 Wm−2 falls on a perfectly reflecting surface at normal incidence. If the surface area is 15 cm2, the average force exerted on the surface is :

if the strain in a wire is not more than 1/1000 and Y = 2 * 10^11 N/m^2, Diameter of wire is 1 mm. The maximum weight hung from the wire is

A proton, a deuteron and an α particle having same momentum enter a uniform magnetic field at right angles to the field. The ratio of their angular momentum with respect to their corresponding centres during their motion in the magnetic field is

37.Define electric dipole moment in terms of torque

If a gas occupies a volume of 300cc at 27 degree C and 620 mm pressure then the volume of the gas at 47 degree C and 640 mm pressure is

Calculate the number of turns in a toroid when the charges of 8 C flows in 1 minute through it, produce a magnetic field of 2.5×10−4 T.[Radius of the toroid is 20 cm]

A particle is performing SHM with an amplitude A and angular frequency ω. Find the displacement of the particle from the mean position where the speed of the particle becomes half of the maximum speed.

Two large plates are held 1.5 mm apart. An electric field of 10^7Vm^- exists between the plates with no electric field outside.What is the charge density on the plates?

A closed hollow insulated cylinder is filled with a gas at 0∘C and also contains an insulated piston of negligible weight and negligible thickness at the middle point. The gas on one side of the piston is heated to 100∘C. If the piston moves by 5 cm, the length of the hollow cylinder is

Radiation of wavelength λ, is incident on a photocell. The fastest emitted electron has speed v. If the wavelength is changed to 3λ4, the speed of the fastest emitted electron will be :

A nucleus of Mass M+Δm is at rest and decays into two daughter nuclei of equal mass M2 each. Speed of light is c. The speed of daughter nuclei is

An uncharged capacitor is fully charged with a battery . the ratio of energy stored in the capacitor to the work done by the battery in this process is

How long will it take sound waves to travel the distance between the points A and B, separated by a distance l, if the air temperature between them varies linearly from T1 to T2? The velocity of sound propagation in air is equal to v=α√TWhere α is a constant.

Two parallel sheets 1 and 2 carry uniform charge densities σ1 and σ2 (σ1>σ2) as shown in figure. The electric field in the region marked II is

The value of k>0 so that the area of the bounded region enclosed between the parabolas y=x−kx2 and y=x2k is maximum, is