50278 + Interview Questions in Physics

1.	let V and E denote the gravitational potential and gravitational field at a point. It is possible ro have (a) V=0 and E=0 (b) V=0 and E not equal to zero (c) V not equal to zero and E=0 (d) V not equal to zero and E not equal to zero
Answer» let V and E denote the gravitational potential and gravitational field at a point. It is possible ro have (a) V=0 and E=0 (b) V=0 and E not equal to zero (c) V not equal to zero and E=0 (d) V not equal to zero and E not equal to zero

Discussion

2.	An object is kept at a distance of 5 cm from a convex mirror, the magnitude of the image distance is
Answer» An object is kept at a distance of 5 cm from a convex mirror, the magnitude of the image distance is

Discussion

3.	20. A particle is released from rest at origin. It moves { under the influence of potential field U=x^2-3x . { Its kinetic energy at x=2 is { (1) 2J{ (2) 1.5J{ (3) 1J (4) Zero
Answer» 20. A particle is released from rest at origin. It moves { under the influence of potential field U=x^2-3x . { Its kinetic energy at x=2 is { (1) 2J{ (2) 1.5J{ (3) 1J (4) Zero

Discussion

4.	5. A U-238 nucleus originally at rest decays by emitting an -alpha particle say with velocity of v m/s. The recoil velocity (in m/s) of the residual nucleus is
Answer» 5. A U-238 nucleus originally at rest decays by emitting an -alpha particle say with velocity of v m/s. The recoil velocity (in m/s) of the residual nucleus is

Discussion

5.	30.a narrow glass tube 80 cm long and opens at both ends, is half immersed in mercury, noe the top of the tube is closed and is taken out of mercury. A columnof mercury 20 cm long remains in the tube. Find atmospheric pressure (1) 20 cm of air column (2) 60 cm of Hg column (3) 60 cm of air column (4) 20 cm of Hg column
Answer» 30.a narrow glass tube 80 cm long and opens at both ends, is half immersed in mercury, noe the top of the tube is closed and is taken out of mercury. A columnof mercury 20 cm long remains in the tube. Find atmospheric pressure (1) 20 cm of air column (2) 60 cm of Hg column (3) 60 cm of air column (4) 20 cm of Hg column

Discussion

6.	A small sphere of radius r falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity is proportional to
Answer» A small sphere of radius r falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity is proportional to

6.

A small sphere of radius r falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity is proportional to

Answer»

A small sphere of radius r falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity is proportional to

Discussion

7.	formula for angle between centripetal acceleration and resul†an t acceleratin
Answer» formula for angle between centripetal acceleration and resul†an t acceleratin

Discussion

8.	Two identical point sources P and Q vibrating in phase with the same amplitude generate sinusoidalwaves on a water surface.The sources are 6.5 cm apart. Two nearest points (from P) of destructiveinterference along PQ are found to be at 0.7 cm and 2.4 cm from P. The total number of points ofdestructive interference on the line segment PQ is(A) 4(B) 3(D)5(C) 2
Answer» Two identical point sources P and Q vibrating in phase with the same amplitude generate sinusoidal waves on a water surface.The sources are 6.5 cm apart. Two nearest points (from P) of destructive interference along PQ are found to be at 0.7 cm and 2.4 cm from P. The total number of points of destructive interference on the line segment PQ is (A) 4 (B) 3 (D)5 (C) 2

Discussion

9.	two charged metallic spheres of radii r1 and r2 are touched and separated calculate the ratio of their 1 charges 2 potential 3 self energy 4 electric field at the surface 5 surface charge den
Answer» two charged metallic spheres of radii r1 and r2 are touched and separated calculate the ratio of their 1 charges 2 potential 3 self energy 4 electric field at the surface 5 surface charge den

Discussion

10.	If the potential difference applied to the photoelectric tube is doubled and the separation between the filament and the target is also doubled, then the cut off wavelength
Answer» If the potential difference applied to the photoelectric tube is doubled and the separation between the filament and the target is also doubled, then the cut off wavelength

Discussion

11.	A wooden block is placed on an inclined plane. Angle of inclination is continuously changed. At 45∘, block starts to slide and continues with uniform speed if angle of inclination is reduced to 30∘. Find μs and μk
Answer» A wooden block is placed on an inclined plane. Angle of inclination is continuously changed. At $45^{\circ}$ , block starts to slide and continues with uniform speed if angle of inclination is reduced to $30^{\circ}$ . Find $μ_{s}$ and $μ_{k}$

Discussion

12.	34. A ball of mass M moving with velocity v collides perfectly inelastically with another ball of mass m The magnitude of impulse imparted to the first ball 1) Mv 2) mv 3) Mmv/(m+M) 4)MMv/M+m
Answer» 34. A ball of mass M moving with velocity v collides perfectly inelastically with another ball of mass m The magnitude of impulse imparted to the first ball 1) Mv 2) mv 3) Mmv/(m+M) 4)MMv/M+m

Discussion

13.	A particle is projected with a velocity of 30 m/s at two angles of 30∘and 60∘ respectively. Then the ratio of their times of flight is
Answer» A particle is projected with a velocity of $30 m/s$ at two angles of $30^{\circ}$ and $60^{\circ}$ respectively. Then the ratio of their times of flight is

Discussion

14.	A room has floor dimensions of 4.0 m x 5.0 m and height of 3.0 m.(a):Find the weight of the air in the room at 20^° c(b)What is the weight of an equal volume of water?(cWhat is the total downward force on the floor surface due to air pressure of 1.0 atm?
Answer» A room has floor dimensions of 4.0 m x 5.0 m and height of 3.0 m.(a):Find the weight of the air in the room at 20^° c(b)What is the weight of an equal volume of water?(cWhat is the total downward force on the floor surface due to air pressure of 1.0 atm?

Discussion

15.	A sphere is rolling on a frictionless surface as shown in the figure with a translational velocity v ms−1. If it is to climb the inclined surface, then v should be
Answer» A sphere is rolling on a frictionless surface as shown in the figure with a translational velocity $v {ms}^{- 1}$ . If it is to climb the inclined surface, then $v$ should be

Discussion

16.	What is the net force experienced by the charge 2 C as shown in the figure.
Answer» What is the net force experienced by the charge $2 C$ as shown in the figure.

Discussion

17.	For a damped oscillator k = 85 N/m, m = 250g and b = 70 g/s. What is the period of oscillation-(1) 0.34 sec.(2) 0.68 sec.(3) 0.20 sec.(4) cannot predict
Answer» For a damped oscillator k = 85 N/m, m = 250g and b = 70 g/s. What is the period of oscillation- (1) 0.34 sec. (2) 0.68 sec. (3) 0.20 sec. (4) cannot predict

Discussion

18.	what is the practical meaning of having time period infinity by a body doing SHM during free fall
Answer» what is the practical meaning of having time period infinity by a body doing SHM during free fall

Discussion

19.	A body at the end of a spring executes S.H.M. with a period t1, while the corresponding period for another spring is t2. If the period of oscillation with the two springs in series is T, then
Answer» A body at the end of a spring executes S.H.M. with a period $t_{1},$ while the corresponding period for another spring is $t_{2} .$ If the period of oscillation with the two springs in series is $T$ , then

Discussion

20.	Two stationary sources A and B produces sound of same frequency. A person running from A to B with cons†an t speed hears 5 beats/s. If frequency of each source decreases by 100 Hz then 3 beats/s is heard then the original frequency of each source will be
Answer» Two stationary sources A and B produces sound of same frequency. A person running from A to B with cons†an t speed hears 5 beats/s. If frequency of each source decreases by 100 Hz then 3 beats/s is heard then the original frequency of each source will be

Discussion

21.	Rain is falling vertically downwards with a velocity of 4 km/h. A man walks in the rain with a velocity of 3 km/h. The raindrops will fall on the man with a velocity of magnitude
Answer» Rain is falling vertically downwards with a velocity of $4 k m / h$ . A man walks in the rain with a velocity of $3 k m / h$ . The raindrops will fall on the man with a velocity of magnitude

Discussion

22.	A potential barrier of 0.5 V exists across a p−n junction. An electron with speed 5.0×105 ms−1 approaches the p−n junction from n−side with what speed will it enter the p−side?(Mass of the electron, m=9.1×10−31 kg)
Answer» A potential barrier of $0.5 V$ exists across a $p - n$ junction. An electron with speed $5.0 \times 10^{5} {ms}^{- 1}$ approaches the $p - n$ junction from $n -$ side with what speed will it enter the $p -$ side? $(Mass of the electron, m = 9.1 \times 10^{- 31} kg)$

Discussion

23.	Q:- A satellite having circular orbit about the earth has a kinetic energy Ex. What is the minimum amount of energy to be added so that it escapes from tge earth? 1. Ex/4 2. Ex/2 3. Ex 4. 2\ast E
Answer» Q:- A satellite having circular orbit about the earth has a kinetic energy Ex. What is the minimum amount of energy to be added so that it escapes from tge earth? 1. Ex/4 2. Ex/2 3. Ex 4. 2\ast E

Discussion

24.	A sonometer wire is stretched by a hanging metal bob. Its fundamental frequency is f1. When the bob is completely immersed in water, the frequency becomes f2. The relative density of the metal is
Answer» A sonometer wire is stretched by a hanging metal bob. Its fundamental frequency is $f_{1}$ . When the bob is completely immersed in water, the frequency becomes $f_{2}$ . The relative density of the metal is

Discussion

25.	The frequency changes by 20% as a source approaches a stationary observer with constant speed vs. What would be the percentage change in frequency as the source recedes from the observer with the same speed? [Given, vs<<v(velocity of sound)]
Answer» The frequency changes by $20 %$ as a source approaches a stationary observer with constant speed $v_{s}$ . What would be the percentage change in frequency as the source recedes from the observer with the same speed? [Given, $v_{s} << v$ (velocity of sound)]

Discussion

26.	The oscillating frequency of a cyclotron is 10 MHz. If the radius of its dees is 0.5 m, then the kinetic energy of a proton accelerated by the cyclotron will be:
Answer» The oscillating frequency of a cyclotron is $10 MHz$ . If the radius of its dees is $0.5 m$ , then the kinetic energy of a proton accelerated by the cyclotron will be:

Discussion

27.	Which one is greater molarity or molity
Answer» Which one is greater molarity or molity

Discussion

28.	Give the location of the centre of mass of a (i) sphere, (ii) cylinder, (iii) ring, and (iv) cube, each of uniform mass density. Does the centre of mass of a body necessarily lie inside the body?
Answer» Give the location of the centre of mass of a (i) sphere, (ii) cylinder, (iii) ring, and (iv) cube, each of uniform mass density. Does the centre of mass of a body necessarily lie inside the body?

Discussion

29.	The electric field in a region is given by →E=(5^i+2^j) N/C. The magnitude of force on a charge of 2 C is
Answer» The electric field in a region is given by $\to E = (5^i + 2^j) N/C$ . The magnitude of force on a charge of $2 C$ is

Discussion

30.	The triple points of neon and carbon dioxide are 24.57 K and 216.55 K respectively. Express these temperatures on the Celsius and Fahrenheit scales
Answer» The triple points of neon and carbon dioxide are 24.57 K and 216.55 K respectively. Express these temperatures on the Celsius and Fahrenheit scales

Discussion

31.	abody of mass 1 kg begins to move under theAction ofa time dependent force F (2ti +3t2jN,and j are unit vectors along x and yWhat power will be developed by the force at the time t
Answer» abody of mass 1 kg begins to move under theAction ofa time dependent force F (2ti +3t2jN,and j are unit vectors along x and yWhat power will be developed by the force at the time t

Discussion

32.	a thin hollow sphere of mass m is completely filled with a liquid of mass m.when the sphere rolls with a velocity v.kinetic energy of the system is
Answer» a thin hollow sphere of mass m is completely filled with a liquid of mass m.when the sphere rolls with a velocity v.kinetic energy of the system is

Discussion

33.	Two rods of lengths a and b slide along the x-axis and y-axis respectively in such a manner that their ends and concyclic. The locus of the centre of the circle passing through the end points is
Answer» Two rods of lengths a and b slide along the x-axis and y-axis respectively in such a manner that their ends and concyclic. The locus of the centre of the circle passing through the end points is

Discussion

34.	What is the coefficient of friction when a cylinder rolls down without slipping on an inclined plane?
Answer» What is the coefficient of friction when a cylinder rolls down without slipping on an inclined plane?

Discussion

35.	Two blocks of unequal masses are tied by a spring. The blocks are pulled stretching the spring slightly and the system is released on a frictionless horizontal platform. Are the forces due to the spring on the two blocks equal and opposite? If yes, is it an example of Newton's third law?
Answer» Two blocks of unequal masses are tied by a spring. The blocks are pulled stretching the spring slightly and the system is released on a frictionless horizontal platform. Are the forces due to the spring on the two blocks equal and opposite? If yes, is it an example of Newton's third law?

Discussion

36.	The centres of two identical small conducting spheres are 1m apart. They carry charges of opposite kind and attract each other with a force F. When they are connected by a conducting thin wire they repel each other with a force F/3. What is the ratio of magnitude of charges carried by the spheres initially?
Answer» The centres of two identical small conducting spheres are 1m apart. They carry charges of opposite kind and attract each other with a force F. When they are connected by a conducting thin wire they repel each other with a force F/3. What is the ratio of magnitude of charges carried by the spheres initially?

Discussion

37.	At time t=0, the displacement of a simple harmonic oscillator from the mean position is 0.2 m and the velocity is 0.5 m/s. What is the amplitude of oscillator if angular frequency is 2π rad/s.
Answer» At time $t = 0$ , the displacement of a simple harmonic oscillator from the mean position is $0.2 m$ and the velocity is $0.5 m/s$ . What is the amplitude of oscillator if angular frequency is $2 π rad/s$ .

Discussion

38.	A projectile is given an initial velocity of (α i+β j)m/s where i is along the ground and j along the vertical. the trajectory is
Answer» A projectile is given an initial velocity of (α i+β j)m/s where i is along the ground and j along the vertical. the trajectory is

Discussion

39.	If 250J of work is done in slidinga5kg blockup an inclined plane of height 4m. Work done agaist friction
Answer» If 250J of work is done in slidinga5kg blockup an inclined plane of height 4m. Work done agaist friction

Discussion

40.	Light of frequency 4v0 is incident on the metal of the threshold frequency v0. The maximum kinetic energy of the emitted photoelectrons is
Answer» Light of frequency $4 v_{0}$ is incident on the metal of the threshold frequency $v_{0}$ . The maximum kinetic energy of the emitted photoelectrons is

Discussion

41.	A capacior of capacitance C is charged to a potential difference V from a cell and then disconnected from it. A charge +Q is now given to its positive plate. The potential difference across the capacitor is now-
Answer» A capacior of capacitance $C$ is charged to a potential difference $V$ from a cell and then disconnected from it. A charge $+ Q$ is now given to its positive plate. The potential difference across the capacitor is now-

Discussion

42.	A transistor can be used as a/an
Answer» A transistor can be used as a/an

Discussion

43.	The figure shows an open tube which contains some water and a less dense liquid poured in on the right-hand side. The density of the unknown liquid, in terms of height hw, hx and density of water ρw is
Answer» The figure shows an open tube which contains some water and a less dense liquid poured in on the right-hand side. The density of the unknown liquid, in terms of height $h_{w}$ , $h_{x}$ and density of water $ρ_{w}$ is

Discussion

44.	Four particles each of mass m are placed at the corners of a square of side length l. The radius of gyration of the system about an axis perpendicular to the square and passing through its centre is
Answer» Four particles each of mass $m$ are placed at the corners of a square of side length $l$ . The radius of gyration of the system about an axis perpendicular to the square and passing through its centre is

Discussion

45.	How to solve: The energy required to dislodge electron from excited isolated H-atom,IE1=13.6eV is
Answer» How to solve: The energy required to dislodge electron from excited isolated H-atom,IE1=13.6eV is

Discussion

46.	The formula to calculate the packing efficiency of the face centred unit cell is:
Answer» The formula to calculate the packing efficiency of the face centred unit cell is:

Discussion

47.	alternating current in an AC circuit varies with time as I(t)=100sin50(pi)t cos50(pi)t.The maximum current and frequency are respectively?
Answer» alternating current in an AC circuit varies with time as I(t)=100sin50(pi)t cos50(pi)t.The maximum current and frequency are respectively?

Discussion

48.	98. A: if an electron and proton possessing same kinetic energy enter an electric field in a perpendicular direction, the path of the electron is more curved than that of the proton R: electron forms a larger curve due to its small mass
Answer» 98. A: if an electron and proton possessing same kinetic energy enter an electric field in a perpendicular direction, the path of the electron is more curved than that of the proton R: electron forms a larger curve due to its small mass

Discussion

49.	75.Magnetic needle oscillates in a horizontal plane with the time period t at a place with angle of dip 60 degree when the same needle is made to oscillate in a vertical plane coinciding with the magnetic meridian its period will be 1)T/2 2)T 3)2T 4)2T
Answer» 75.Magnetic needle oscillates in a horizontal plane with the time period t at a place with angle of dip 60 degree when the same needle is made to oscillate in a vertical plane coinciding with the magnetic meridian its period will be 1)T/2 2)T 3)2T 4)2T

Discussion

50.	wo identical infinite positive line charges areplaced along the lines X ta in the x-y plane. Apositive point charge placed at origin is restrictedto move along x-axis. Its equilibrium isx-ax=+a(1) Unstable(2) Stable3 Neutral(4) None of these
Answer» wo identical infinite positive line charges areplaced along the lines X ta in the x-y plane. Apositive point charge placed at origin is restrictedto move along x-axis. Its equilibrium isx-ax=+a(1) Unstable(2) Stable3 Neutral(4) None of these

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

let V and E denote the gravitational potential and gravitational field at a point. It is possible ro have (a) V=0 and E=0 (b) V=0 and E not equal to zero (c) V not equal to zero and E=0 (d) V not equal to zero and E not equal to zero

An object is kept at a distance of 5 cm from a convex mirror, the magnitude of the image distance is

20. A particle is released from rest at origin. It moves { under the influence of potential field U=x^2-3x . { Its kinetic energy at x=2 is { (1) 2J{ (2) 1.5J{ (3) 1J (4) Zero

5. A U-238 nucleus originally at rest decays by emitting an -alpha particle say with velocity of v m/s. The recoil velocity (in m/s) of the residual nucleus is

A small sphere of radius r falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity is proportional to

formula for angle between centripetal acceleration and resul†an t acceleratin

two charged metallic spheres of radii r1 and r2 are touched and separated calculate the ratio of their 1 charges 2 potential 3 self energy 4 electric field at the surface 5 surface charge den

If the potential difference applied to the photoelectric tube is doubled and the separation between the filament and the target is also doubled, then the cut off wavelength

A wooden block is placed on an inclined plane. Angle of inclination is continuously changed. At 45∘, block starts to slide and continues with uniform speed if angle of inclination is reduced to 30∘. Find μs and μk

34. A ball of mass M moving with velocity v collides perfectly inelastically with another ball of mass m The magnitude of impulse imparted to the first ball 1) Mv 2) mv 3) Mmv/(m+M) 4)MMv/M+m

A particle is projected with a velocity of 30 m/s at two angles of 30∘and 60∘ respectively. Then the ratio of their times of flight is

A room has floor dimensions of 4.0 m x 5.0 m and height of 3.0 m.(a):Find the weight of the air in the room at 20^° c(b)What is the weight of an equal volume of water?(cWhat is the total downward force on the floor surface due to air pressure of 1.0 atm?

A sphere is rolling on a frictionless surface as shown in the figure with a translational velocity v ms−1. If it is to climb the inclined surface, then v should be

What is the net force experienced by the charge 2 C as shown in the figure.

For a damped oscillator k = 85 N/m, m = 250g and b = 70 g/s. What is the period of oscillation-(1) 0.34 sec.(2) 0.68 sec.(3) 0.20 sec.(4) cannot predict

what is the practical meaning of having time period infinity by a body doing SHM during free fall

A body at the end of a spring executes S.H.M. with a period t1, while the corresponding period for another spring is t2. If the period of oscillation with the two springs in series is T, then

Two stationary sources A and B produces sound of same frequency. A person running from A to B with cons†an t speed hears 5 beats/s. If frequency of each source decreases by 100 Hz then 3 beats/s is heard then the original frequency of each source will be

Rain is falling vertically downwards with a velocity of 4 km/h. A man walks in the rain with a velocity of 3 km/h. The raindrops will fall on the man with a velocity of magnitude

A potential barrier of 0.5 V exists across a p−n junction. An electron with speed 5.0×105 ms−1 approaches the p−n junction from n−side with what speed will it enter the p−side?(Mass of the electron, m=9.1×10−31 kg)

Q:- A satellite having circular orbit about the earth has a kinetic energy Ex. What is the minimum amount of energy to be added so that it escapes from tge earth? 1. Ex/4 2. Ex/2 3. Ex 4. 2\ast E

A sonometer wire is stretched by a hanging metal bob. Its fundamental frequency is f1. When the bob is completely immersed in water, the frequency becomes f2. The relative density of the metal is

The frequency changes by 20% as a source approaches a stationary observer with constant speed vs. What would be the percentage change in frequency as the source recedes from the observer with the same speed? [Given, vs&lt;&lt;v(velocity of sound)]

The oscillating frequency of a cyclotron is 10 MHz. If the radius of its dees is 0.5 m, then the kinetic energy of a proton accelerated by the cyclotron will be:

Which one is greater molarity or molity

Give the location of the centre of mass of a (i) sphere, (ii) cylinder, (iii) ring, and (iv) cube, each of uniform mass density. Does the centre of mass of a body necessarily lie inside the body?

The electric field in a region is given by →E=(5^i+2^j) N/C. The magnitude of force on a charge of 2 C is

The triple points of neon and carbon dioxide are 24.57 K and 216.55 K respectively. Express these temperatures on the Celsius and Fahrenheit scales

abody of mass 1 kg begins to move under theAction ofa time dependent force F (2ti +3t2jN,and j are unit vectors along x and yWhat power will be developed by the force at the time t

a thin hollow sphere of mass m is completely filled with a liquid of mass m.when the sphere rolls with a velocity v.kinetic energy of the system is

Two rods of lengths a and b slide along the x-axis and y-axis respectively in such a manner that their ends and concyclic. The locus of the centre of the circle passing through the end points is

What is the coefficient of friction when a cylinder rolls down without slipping on an inclined plane?

Two blocks of unequal masses are tied by a spring. The blocks are pulled stretching the spring slightly and the system is released on a frictionless horizontal platform. Are the forces due to the spring on the two blocks equal and opposite? If yes, is it an example of Newton's third law?

At time t=0, the displacement of a simple harmonic oscillator from the mean position is 0.2 m and the velocity is 0.5 m/s. What is the amplitude of oscillator if angular frequency is 2π rad/s.

A projectile is given an initial velocity of (α i+β j)m/s where i is along the ground and j along the vertical. the trajectory is

If 250J of work is done in slidinga5kg blockup an inclined plane of height 4m. Work done agaist friction

Light of frequency 4v0 is incident on the metal of the threshold frequency v0. The maximum kinetic energy of the emitted photoelectrons is

A capacior of capacitance C is charged to a potential difference V from a cell and then disconnected from it. A charge +Q is now given to its positive plate. The potential difference across the capacitor is now-

A transistor can be used as a/an

The figure shows an open tube which contains some water and a less dense liquid poured in on the right-hand side. The density of the unknown liquid, in terms of height hw, hx and density of water ρw is

Four particles each of mass m are placed at the corners of a square of side length l. The radius of gyration of the system about an axis perpendicular to the square and passing through its centre is

How to solve: The energy required to dislodge electron from excited isolated H-atom,IE1=13.6eV is

The formula to calculate the packing efficiency of the face centred unit cell is:

alternating current in an AC circuit varies with time as I(t)=100sin50(pi)t cos50(pi)t.The maximum current and frequency are respectively?

98. A: if an electron and proton possessing same kinetic energy enter an electric field in a perpendicular direction, the path of the electron is more curved than that of the proton R: electron forms a larger curve due to its small mass

75.Magnetic needle oscillates in a horizontal plane with the time period t at a place with angle of dip 60 degree when the same needle is made to oscillate in a vertical plane coinciding with the magnetic meridian its period will be 1)T/2 2)T 3)2T 4)2T

wo identical infinite positive line charges areplaced along the lines X ta in the x-y plane. Apositive point charge placed at origin is restrictedto move along x-axis. Its equilibrium isx-ax=+a(1) Unstable(2) Stable3 Neutral(4) None of these

The frequency changes by 20% as a source approaches a stationary observer with constant speed vs. What would be the percentage change in frequency as the source recedes from the observer with the same speed? [Given, vs<<v(velocity of sound)]