50278 + Interview Questions in Physics

1.	the maxium power that can be generated in a external resistor ofcell of emf10V and internal resis†an ce 2 ohm
Answer» the maxium power that can be generated in a external resistor ofcell of emf10V and internal resis†an ce 2 ohm

Discussion

2.	The function rule that relate the given function's input and output is .
Answer» The function rule that relate the given function's input and output is .

Discussion

3.	21.A person watvhing throgh the window of an apartment sees a ball that rises vertically up and then vertically down for a total time of 0.5 s. If the height of the window is 2m, find the maximum height above the window reached by the ball.
Answer» 21.A person watvhing throgh the window of an apartment sees a ball that rises vertically up and then vertically down for a total time of 0.5 s. If the height of the window is 2m, find the maximum height above the window reached by the ball.

Discussion

4.	one of the rectangular component of a force of 40N is 20N find the vector P
Answer» one of the rectangular component of a force of 40N is 20N find the vector P

Discussion

5.	The minimum force needed to punch a hole of radius r in an iron plate of thickness d is \{ The ultimate shear stress of the iron is η \
Answer» The minimum force needed to punch a hole of radius r in an iron plate of thickness d is \{ The ultimate shear stress of the iron is η \

Discussion

6.	Ratio of electrostatic force and gravitational force between proton and proton
Answer» Ratio of electrostatic force and gravitational force between proton and proton

Discussion

7.	Root mean square velocity of a gas molecule is proportional to
Answer» Root mean square velocity of a gas molecule is proportional to

7.

Root mean square velocity of a gas molecule is proportional to

Answer»

Root mean square velocity of a gas molecule is proportional to

Discussion

8.	128Magnetism and Matter10.Two short magnets of equal dipole moments M arefastened perpendicularly at their centres as shownbelow (point P is in the plane of the magnets)The magnetic field (magnitude) at P, distance d fromthe centre on the bisector of the right angle isHo Mv2(1) 4T dHo 2M
Answer» 128Magnetism and Matter10.Two short magnets of equal dipole moments M arefastened perpendicularly at their centres as shownbelow (point P is in the plane of the magnets)The magnetic field (magnitude) at P, distance d fromthe centre on the bisector of the right angle isHo Mv2(1) 4T dHo 2M

Discussion

9.	A spherical conductor of radius 4 cm carries a charge of 1.11×10–10 C. At what distance (in cm) from the centre of sphere should a point charge of 4.44×10–10 C be placed so that the potential of the conductor becomes 50 V? (integer only)[Assume V=0 at ∞]
Answer» A spherical conductor of radius $4 cm$ carries a charge of $1.11 \times 10^{- 10} C$ . At what distance (in $cm$ ) from the centre of sphere should a point charge of $4.44 \times 10^{- 10} C$ be placed so that the potential of the conductor becomes $50 V ?$ (integer only) [Assume $V = 0 at \infty$ ]

Discussion

10.	A dielectric slab of dielectric constant K is placed between the plates of a parallel plate capacitor carryingcharge q. The induced charge q' on the surface of slab is given by
Answer» A dielectric slab of dielectric constant K is placed between the plates of a parallel plate capacitor carrying charge q. The induced charge q' on the surface of slab is given by

Discussion

11.	A block A of mass 5 kg rests over another block B of mass 3 kg placed over a smooth horizontal surface. There is friction between A and B. A horizontal force F1 gradually increasing from zero to a maximum value is applied to A so that the blocks move together without relative motion. Instead of this, another horizontal force F2 gradually increasing from zero to a maximum value is applied to B so that the blocks moves together without relative motion. Then -
Answer» A block $A$ of mass $5 kg$ rests over another block $B$ of mass $3 kg$ placed over a smooth horizontal surface. There is friction between $A$ and $B$ . A horizontal force $F_{1}$ gradually increasing from zero to a maximum value is applied to $A$ so that the blocks move together without relative motion. Instead of this, another horizontal force $F_{2}$ gradually increasing from zero to a maximum value is applied to $B$ so that the blocks moves together without relative motion. Then -

Discussion

12.	A block is kept on an inclined plane of inclination 0 of length I. The velocity of the particle at the bottom of inclined is (Thecoefficient of friction is H):Options:/2gl(ucos-sine)2g(sine- μ cosθ )2g(sin6+ μ ε osθ )y2g!(cose+ usine)
Answer» A block is kept on an inclined plane of inclination 0 of length I. The velocity of the particle at the bottom of inclined is (The coefficient of friction is H): Options: /2gl(ucos-sine) 2g(sine- μ cosθ ) 2g(sin6+ μ ε osθ ) y2g!(cose+ usine)

Discussion

13.	A coil of resistance 300 Ω and inductance 1.0 H is connected across an alternating voltage of frequency 3002π Hz. Calculate the phase difference between the voltage and the current in the circuit.
Answer» A coil of resistance $300 Ω$ and inductance $1.0 H$ is connected across an alternating voltage of frequency $\frac{300}{2 π} Hz$ . Calculate the phase difference between the voltage and the current in the circuit.

Discussion

14.	A boggy of uniformly moving train is suddenly detached from train and stops after covering some distance. The ratio of distance covered by the boggy and distance covered by the train when the boggy has stopped is
Answer» A boggy of uniformly moving train is suddenly detached from train and stops after covering some distance. The ratio of distance covered by the boggy and distance covered by the train when the boggy has stopped is

Discussion

15.	A particle of mass 2kg is moving in circular path with constant speed 20 m/s. Find the magnitude of change in velocity when particle moved such that line joining the particle to center sweeps the angle 90^° .
Answer» A particle of mass 2kg is moving in circular path with constant speed 20 m/s. Find the magnitude of change in velocity when particle moved such that line joining the particle to center sweeps the angle 90^° .

Discussion

16.	A beam of light strikes a piece of glass at an angle of incidence of 60∘ and the reflected beam is completely plane polarized. The refractive index of the glass is equal to
Answer» A beam of light strikes a piece of glass at an angle of incidence of $60^{\circ}$ and the reflected beam is completely plane polarized. The refractive index of the glass is equal to

Discussion

17.	The old gramophone record player spins the disc at a constant frequency of 75 Hz. Find the average angular velocity of the disk.
Answer» The old gramophone record player spins the disc at a constant frequency of $75 Hz$ . Find the average angular velocity of the disk.

Discussion

18.	The work done to raise a mass m from the surface of the earth to a height h which is equal to the radius of the earth
Answer» The work done to raise a mass m from the surface of the earth to a height h which is equal to the radius of the earth

Discussion

19.	A periodic signal x(t) has a trigonometric Fourier series expansion x(t)=a0+∑∝n=1(ancosnω0t+bnsinnω0t) If x(t) = -x(-t) =−x(t−πω0). We can conclude that
Answer» A periodic signal x(t) has a trigonometric Fourier series expansion $x (t) = a_{0} + \sum_{n = 1}^{\propto} (a_{n} cos n ω_{0} t + b_{n} sin n ω_{0} t)$ If x(t) = -x(-t) $= - x (t - \frac{π}{ω_{0}})$ . We can conclude that

Discussion

20.	Cu?aq) te oing 2n The electrode potentials for Cu and Cuee teCuo) are +0.15 V respectively. The value of Eo CuaCu will be o [AIPMT (Prelims)-2011) (2) 0.500 V (4) 0.650V (1) 0.150V (3) 0.325 V 21. Standard electrode potential for Sn4t (Sn2+ o
Answer» Cu?aq) te oing 2n The electrode potentials for Cu and Cuee teCuo) are +0.15 V respectively. The value of Eo CuaCu will be o [AIPMT (Prelims)-2011) (2) 0.500 V (4) 0.650V (1) 0.150V (3) 0.325 V 21. Standard electrode potential for Sn4t (Sn2+ o

Discussion

21.	Suppose the platform of the previous problem is brought to rest with the ball in the hand of the kid standing on the rim. The kid throws the ball horizontally to his friend in a direction tangential to the rim with a speed v as seen by his friend. Find the angular velocity with which the platform will start rotating.
Answer» Suppose the platform of the previous problem is brought to rest with the ball in the hand of the kid standing on the rim. The kid throws the ball horizontally to his friend in a direction tangential to the rim with a speed v as seen by his friend. Find the angular velocity with which the platform will start rotating.

Discussion

22.	why change in the position is considered as displacement ? { in the defination of avg velocity it is written that it is defined as the change in the position or displacement of object
Answer» why change in the position is considered as displacement ? { in the defination of avg velocity it is written that it is defined as the change in the position or displacement of object

Discussion

23.	Two closed vessels A, B are at same temperature T and contain gases which obey maxwellian distribution of velocities. Vessel A contains O2, and B contain mixture of H2 and O2. If the average speed of the O2 molecule in vessel A is v1, then average speed of H2 in container B is
Answer» Two closed vessels A, B are at same temperature T and contain gases which obey maxwellian distribution of velocities. Vessel A contains O2, and B contain mixture of H2 and O2. If the average speed of the O2 molecule in vessel A is v1, then average speed of H2 in container B is

Discussion

24.	According to Gauss' Theorem, electric field of an infinitely long straight wire is proportional to
Answer» According to Gauss' Theorem, electric field of an infinitely long straight wire is proportional to

24.

According to Gauss' Theorem, electric field of an infinitely long straight wire is proportional to

Answer»

According to Gauss' Theorem, electric field of an infinitely long straight wire is proportional to

Discussion

25.	A projectile attains the escape velocity when :
Answer» A projectile attains the escape velocity when :

Discussion

26.	An electron jumps from the 4th orbit to the 2nd orbit of hydrogen atom. Given Rydberg's constant R=105 cm−1.The frequency of the emitted radiation will be (in Hz)
Answer» An electron jumps from the $4^{t h}$ orbit to the $2^{n d}$ orbit of hydrogen atom. Given Rydberg's constant $R = 10^{5} {cm}^{- 1} .$ The frequency of the emitted radiation will be (in $Hz$ )

Discussion

27.	The masses and radii of the earth and moon are M1,R1 and M2,R2 respectively. Their centres are distance d apart. The minimum velocity with which a particle of mass m should be projected from a point midway between their centres so that it escapes to infinity is
Answer» The masses and radii of the earth and moon are $M_{1}, R_{1} a n d M_{2}, R_{2}$ respectively. Their centres are distance d apart. The minimum velocity with which a particle of mass m should be projected from a point midway between their centres so that it escapes to infinity is

Discussion

28.	what is bulk modulus?
Answer» what is bulk modulus?

Discussion

29.	Particle executing shm along y axis has its motion described by exuation y =2+10sin5¥t amplitude of shm where ¥=omega
Answer» Particle executing shm along y axis has its motion described by exuation y =2+10sin5¥t amplitude of shm where ¥=omega

Discussion

30.	A body is projected with speed 55 m/s . Find the distance travelled by it in 6th second of it motion
Answer» A body is projected with speed 55 m/s . Find the distance travelled by it in 6th second of it motion

Discussion

31.	Photoelectric emission is observed from a metallic surface for frequencies v1 and v2 and of the incident light rays (v1>v2). If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio of 1 : k, then the threshold frequency of the metallic surface is
Answer» Photoelectric emission is observed from a metallic surface for frequencies $v_{1}$ and $v_{2}$ and of the incident light rays $(v_{1} > v_{2})$ . If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio of 1 : k, then the threshold frequency of the metallic surface is

Discussion

32.	An isocles triangle is formed by the co ordinate aces and Line 2x+y=a. The area of the triangle would be
Answer» An isocles triangle is formed by the co ordinate aces and Line 2x+y=a. The area of the triangle would be

Discussion

33.	For the R-L circuit shown in the figure, the input voltage Vi(t)=u(t). The current i(t) is
Answer» For the R-L circuit shown in the figure, the input voltage $V_{i} (t) = u (t)$ . The current $i (t)$ is

Discussion

34.	The equation of motion of a projectile is y=12x−34x2. The horizontal component of velocity is 3 ms−1. What is the range of the projectile in meter?
Answer» The equation of motion of a projectile is $y = 12 x - \frac{3}{4} x^{2}$ . The horizontal component of velocity is $3 m s^{- 1}$ . What is the range of the projectile in meter?

Discussion

35.	A person brings a mass of 2 kg from point A to B. The increase in kinetic energy of the body is 4 J and the work done by the person is -10 J. Find the potential difference between points A and B.
Answer» A person brings a mass of 2 kg from point A to B. The increase in kinetic energy of the body is 4 J and the work done by the person is -10 J. Find the potential difference between points A and B.

Discussion

36.	Find the M.O.I (I) of a uniform solid sphere of radius R and mass M about its tangent
Answer» Find the M.O.I $(I)$ of a uniform solid sphere of radius $R$ and mass $M$ about its tangent

Discussion

37.	Derive the value of G (Universal Gravitational Cons†an t) in SI Units
Answer» Derive the value of G (Universal Gravitational Cons†an t) in SI Units

Discussion

38.	The F−X curve is shown below. Find the change in potential energy when particle displaces from X=0 m to X=6 m (Assume SI units)
Answer» The $F - X$ curve is shown below. Find the change in potential energy when particle displaces from $X = 0 m$ to $X = 6 m$ (Assume SI units)

Discussion

39.	For x>0 and arbitrary constant of integration C, ∫xx(1x+(lnx)2+lnx)dx is equal to
Answer» For $x > 0$ and arbitrary constant of integration $C,$ $\int x^{x} (\frac{1}{x} + (ln x)^{2} + ln x) d x$ is equal to

Discussion

40.	A parallel plate capacitor of capacitance 10μF is connected across a battery of e.m.f. 5 mV. Now, the space between the plates of the capacitor is filled with a dielectric material of dielectric constant K=5. Then, the charge that flows through the battery, till equilibrium is reached is
Answer» A parallel plate capacitor of capacitance $10 μ F$ is connected across a battery of e.m.f. $5 m V$ . Now, the space between the plates of the capacitor is filled with a dielectric material of dielectric constant $K = 5$ . Then, the charge that flows through the battery, till equilibrium is reached is

Discussion

41.	two postive charge of 10 microC and 5 miliC are placed at 1m apart. then work need to bring them 0.5 m close is
Answer» two postive charge of 10 microC and 5 miliC are placed at 1m apart. then work need to bring them 0.5 m close is

Discussion

42.	nttwo uniform solid spheres hving unequal masses and unequal radii are released rest from the same height on a rough incline. If the sphere roll without slippingn nta. the heavier sphere reaches the bottom firstn ntb. the bigger sphere reaches the bottom firstn ntc. the two spheres reach the bottom togethern ntd. the information given is not sufficient to tell which sphere will reach the bottom firstn ntn
Answer» nttwo uniform solid spheres hving unequal masses and unequal radii are released rest from the same height on a rough incline. If the sphere roll without slippingn nta. the heavier sphere reaches the bottom firstn ntb. the bigger sphere reaches the bottom firstn ntc. the two spheres reach the bottom togethern ntd. the information given is not sufficient to tell which sphere will reach the bottom firstn ntn

Discussion

43.	Radiation force experienced by a body (shown in the figure) exposed to radiation of intensity I assuming the surface of the body to be perfectly reflecting is (c is the velocity of light)
Answer» Radiation force experienced by a body (shown in the figure) exposed to radiation of intensity $I$ assuming the surface of the body to be perfectly reflecting is ( $c$ is the velocity of light)

Discussion

44.	A rod of length l=0.5 m is rotating with an angular speed ω=10 rad/s about its one end which is at a distance a=1 m from an infinitely long wire carrying current i=1 A. Find the emf induced in the rod at the instant shown in the figure. Rod and wire both are lying in the same plane.
Answer» A rod of length $l = 0.5 m$ is rotating with an angular speed $ω = 10 rad/s$ about its one end which is at a distance $a = 1 m$ from an infinitely long wire carrying current $i = 1 A .$ Find the emf induced in the rod at the instant shown in the figure. Rod and wire both are lying in the same plane.

Discussion

45.	A pendulum has time period T for small oscillations. An obstacle P is situated below the point of suspension O at a distance 3l4. The pendulum is released from rest. Throughout the motion the moving string makes small angle with vertical. Time after which the pendulum returns back to its initial position is
Answer» A pendulum has time period T for small oscillations. An obstacle P is situated below the point of suspension O at a distance $\frac{3 l}{4}$ . The pendulum is released from rest. Throughout the motion the moving string makes small angle with vertical. Time after which the pendulum returns back to its initial position is

45.

A pendulum has time period T for small oscillations. An obstacle P is situated below the point of suspension O at a distance 3l4. The pendulum is released from rest. Throughout the motion the moving string makes small angle with vertical. Time after which the pendulum returns back to its initial position is

Answer»

A pendulum has time period T for small oscillations. An obstacle P is situated below the point of suspension O at a distance $\frac{3 l}{4}$ . The pendulum is released from rest. Throughout the motion the moving string makes small angle with vertical. Time after which the pendulum returns back to its initial position is

Discussion

46.	A particle of mass 3 kg moves along a straight line 4y−3x=2 (x and y are in m) with constant velocity 5 m/s. The magnitude of its angular momentum about the origin is
Answer» A particle of mass $3 kg$ moves along a straight line $4 y - 3 x = 2$ ( $x$ and $y$ are in $m$ ) with constant velocity $5 m/s$ . The magnitude of its angular momentum about the origin is

Discussion

47.	The length of an elastic string is x metres when the tension is 8 newton, and y metres when the tension is 10 newton. The length in metres when the tension is 18 newton is ?
Answer» The length of an elastic string is x metres when the tension is 8 newton, and y metres when the tension is 10 newton. The length in metres when the tension is 18 newton is ?

Discussion

48.	Find out the phase constant ϕ [in rad] of a particle performing SHM, if the initial conditions are as shown in the figure.
Answer» Find out the phase constant $ϕ$ [in $rad$ ] of a particle performing SHM, if the initial conditions are as shown in the figure.

Discussion

49.	Proof that if any body sleep down respectively an incline plane then its accelaration decreases u=meu mgcosthita
Answer» Proof that if any body sleep down respectively an incline plane then its accelaration decreases u=meu mgcosthita

Discussion

50.	What can be the unit vector of a plane to which a perpendicular dropped from origin(o) meet at A(1, 4, 6)?
Answer» What can be the unit vector of a plane to which a perpendicular dropped from origin(o) meet at A(1, 4, 6)?

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

the maxium power that can be generated in a external resistor ofcell of emf10V and internal resis†an ce 2 ohm

The function rule that relate the given function's input and output is .

21.A person watvhing throgh the window of an apartment sees a ball that rises vertically up and then vertically down for a total time of 0.5 s. If the height of the window is 2m, find the maximum height above the window reached by the ball.

one of the rectangular component of a force of 40N is 20N find the vector P

The minimum force needed to punch a hole of radius r in an iron plate of thickness d is \{ The ultimate shear stress of the iron is η \

Ratio of electrostatic force and gravitational force between proton and proton

Root mean square velocity of a gas molecule is proportional to

128Magnetism and Matter10.Two short magnets of equal dipole moments M arefastened perpendicularly at their centres as shownbelow (point P is in the plane of the magnets)The magnetic field (magnitude) at P, distance d fromthe centre on the bisector of the right angle isHo Mv2(1) 4T dHo 2M

A spherical conductor of radius 4 cm carries a charge of 1.11×10–10 C. At what distance (in cm) from the centre of sphere should a point charge of 4.44×10–10 C be placed so that the potential of the conductor becomes 50 V? (integer only)[Assume V=0 at ∞]

A dielectric slab of dielectric constant K is placed between the plates of a parallel plate capacitor carryingcharge q. The induced charge q' on the surface of slab is given by

A block is kept on an inclined plane of inclination 0 of length I. The velocity of the particle at the bottom of inclined is (Thecoefficient of friction is H):Options:/2gl(ucos-sine)2g(sine- μ cosθ )2g(sin6+ μ ε osθ )y2g!(cose+ usine)

A coil of resistance 300 Ω and inductance 1.0 H is connected across an alternating voltage of frequency 3002π Hz. Calculate the phase difference between the voltage and the current in the circuit.

A boggy of uniformly moving train is suddenly detached from train and stops after covering some distance. The ratio of distance covered by the boggy and distance covered by the train when the boggy has stopped is

A particle of mass 2kg is moving in circular path with constant speed 20 m/s. Find the magnitude of change in velocity when particle moved such that line joining the particle to center sweeps the angle 90^° .

A beam of light strikes a piece of glass at an angle of incidence of 60∘ and the reflected beam is completely plane polarized. The refractive index of the glass is equal to

The old gramophone record player spins the disc at a constant frequency of 75 Hz. Find the average angular velocity of the disk.

The work done to raise a mass m from the surface of the earth to a height h which is equal to the radius of the earth

A periodic signal x(t) has a trigonometric Fourier series expansion x(t)=a0+∑∝n=1(ancosnω0t+bnsinnω0t) If x(t) = -x(-t) =−x(t−πω0). We can conclude that

Cu?aq) te oing 2n The electrode potentials for Cu and Cuee teCuo) are +0.15 V respectively. The value of Eo CuaCu will be o [AIPMT (Prelims)-2011) (2) 0.500 V (4) 0.650V (1) 0.150V (3) 0.325 V 21. Standard electrode potential for Sn4t (Sn2+ o

why change in the position is considered as displacement ? { in the defination of avg velocity it is written that it is defined as the change in the position or displacement of object

Two closed vessels A, B are at same temperature T and contain gases which obey maxwellian distribution of velocities. Vessel A contains O2, and B contain mixture of H2 and O2. If the average speed of the O2 molecule in vessel A is v1, then average speed of H2 in container B is

According to Gauss' Theorem, electric field of an infinitely long straight wire is proportional to

A projectile attains the escape velocity when :

An electron jumps from the 4th orbit to the 2nd orbit of hydrogen atom. Given Rydberg's constant R=105 cm−1.The frequency of the emitted radiation will be (in Hz)

The masses and radii of the earth and moon are M1,R1 and M2,R2 respectively. Their centres are distance d apart. The minimum velocity with which a particle of mass m should be projected from a point midway between their centres so that it escapes to infinity is

what is bulk modulus?

Particle executing shm along y axis has its motion described by exuation y =2+10sin5¥t amplitude of shm where ¥=omega

A body is projected with speed 55 m/s . Find the distance travelled by it in 6th second of it motion

Photoelectric emission is observed from a metallic surface for frequencies v1 and v2 and of the incident light rays (v1&gt;v2). If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio of 1 : k, then the threshold frequency of the metallic surface is

An isocles triangle is formed by the co ordinate aces and Line 2x+y=a. The area of the triangle would be

For the R-L circuit shown in the figure, the input voltage Vi(t)=u(t). The current i(t) is

The equation of motion of a projectile is y=12x−34x2. The horizontal component of velocity is 3 ms−1. What is the range of the projectile in meter?

A person brings a mass of 2 kg from point A to B. The increase in kinetic energy of the body is 4 J and the work done by the person is -10 J. Find the potential difference between points A and B.

Find the M.O.I (I) of a uniform solid sphere of radius R and mass M about its tangent

Derive the value of G (Universal Gravitational Cons†an t) in SI Units

The F−X curve is shown below. Find the change in potential energy when particle displaces from X=0 m to X=6 m (Assume SI units)

For x&gt;0 and arbitrary constant of integration C, ∫xx(1x+(lnx)2+lnx)dx is equal to

A parallel plate capacitor of capacitance 10μF is connected across a battery of e.m.f. 5 mV. Now, the space between the plates of the capacitor is filled with a dielectric material of dielectric constant K=5. Then, the charge that flows through the battery, till equilibrium is reached is

two postive charge of 10 microC and 5 miliC are placed at 1m apart. then work need to bring them 0.5 m close is

Radiation force experienced by a body (shown in the figure) exposed to radiation of intensity I assuming the surface of the body to be perfectly reflecting is (c is the velocity of light)

A rod of length l=0.5 m is rotating with an angular speed ω=10 rad/s about its one end which is at a distance a=1 m from an infinitely long wire carrying current i=1 A. Find the emf induced in the rod at the instant shown in the figure. Rod and wire both are lying in the same plane.

A particle of mass 3 kg moves along a straight line 4y−3x=2 (x and y are in m) with constant velocity 5 m/s. The magnitude of its angular momentum about the origin is

The length of an elastic string is x metres when the tension is 8 newton, and y metres when the tension is 10 newton. The length in metres when the tension is 18 newton is ?

Find out the phase constant ϕ [in rad] of a particle performing SHM, if the initial conditions are as shown in the figure.

Proof that if any body sleep down respectively an incline plane then its accelaration decreases u=meu mgcosthita

What can be the unit vector of a plane to which a perpendicular dropped from origin(o) meet at A(1, 4, 6)?

Photoelectric emission is observed from a metallic surface for frequencies v1 and v2 and of the incident light rays (v1>v2). If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio of 1 : k, then the threshold frequency of the metallic surface is

For x>0 and arbitrary constant of integration C, ∫xx(1x+(lnx)2+lnx)dx is equal to