41 Questions
| Total Attempts: 300

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Questions and Answers

- 1..The electric flux is given D = (2y
^{2}+ z) I_{x}+ 4xy I_{y}+ x 1_{z}C/m^{2}(I_{x},I_{y }and I_{z }are the unit vectors along x , y and z directions). The volume charge density at point (-1,0,3) is- A.
0 C/m3.

- B.
- 2 C/m3.

- C.
- 4 C/m3.

- D.
- 8 C/m3

- 2.Gradient of scalar field is expressed as
- A.
Outward flux of a vector field per unit volume as the volume about the point tends to zero.

- B.
Gradient of divergence of a vector field minus the curl of the vector field.

- C.
Circulation of a vector field per unit area as the area tends to zero.

- D.
Maximum rate of increase of scalar function at appoint.

- 3.Which of following is zero?
- A.
Grad div A.

- B.
Div Gradient V.

- C.
Div curl A.

- D.
Curl curl A.

- 4.Which statement does not say that electrostatic field conservative?
- A.
If the curl of E is identically zero.

- B.
The potential difference between two points is zero.

- C.
If is gradient of a scalar potential.

- D.
The work done in a closed path inside the fields is zero.

- 5.If E is the electric field intensity, then what is the value of divergence of (curl of E)?.
- A.
E.

- B.
| E |.

- C.
Null vector.

- D.
Zero.

- 6.Two sphere of radius r
_{1}and r_{2}are connected by a conducting wire. Each of the spheres has been given a charge Q. Now- A.
Larger sphere will have greater potential.

- B.
Larger sphere will have smalled potential.

- C.
Both of sphere will have same potential

- D.
Smaller sphere will have zero potential.

- 7.
- A.
Both are zero.

- B.
It is zero for the electric flux density.

- C.
These are zero for static densities but non zero for time varying densities.

- D.
It is zero for the magnetic flux density.

- 8.
- A.
It is conservatives.

- B.
It is solenoidal.

- C.
It has no sink or sources.

- D.
Magnetic flux lines are always closed.

- 9.For gauss's law the point charges in closed surface must be distributed
- A.
arbitrarily

- B.
sequentially

- C.
rational

- D.
in line

- 10.Gauss's law due to different charge distribution is used to calculate
- A.
electric field

- B.
electric charge

- C.
electric intensity

- D.
electric field lines

- 11.The field lines parallel to the sides of box will have flux that is
- A.
1

- B.
min

- C.
0

- D.
Max

- 12.The law stated as flux is 1/eo times the total charge is
- A.
Ohms law

- B.
Newton's law

- C.
Gauss's law

- D.
Coulombs law

- 13.The law stating the force directly proportional to charges and inversely proportional to the square of radius is called
- A.
Newton's law

- B.
Coulombs law

- C.
Gauss's law

- D.
4ohms law

- 14.Two positive charges q
_{1}= 16 and q_{2}= 4 are separated by a diameter of 3m will produce the force of- A.
40N

- B.
41.1N

- C.
42.3N

- D.
42.7N

- 15.The formula that describes the statement of the coulombs law is
- A.
F = kq1q2/r2

- B.
F = q1q2/r2

- C.
F = kq2/r2

- D.
F = kq1q2/r

- 16.Two metal spheres of radii R
_{1}and R_{2}are charged to the same potential. The ratio of charges on the spheres 1 and 2 is- A.
√R1 : √R2

- B.
1:1

- C.
R1 : R2

- D.
R1³ : R2³

- 17.A simple pendulum has a metal bob, which is negatively charged. If it is allowed to oscillate above. a positively charged metallic piate, then its time period will
- A.
Increases

- B.
Become zero

- C.
Decreases

- D.
Remain the same

- 18.A sphere of radius 1 em has potential of 8000 V, then energy density near its surface will be
- A.
64 x 10⁵ J/m³

- B.
8 x 10³ J/m³

- C.
32 J/m³

- D.
2.83 J/m³

- 19.Two plates are 2 cm apart, a potential is applied between them, the electric field difference of 10 volts is applied between them, the electric field between the plates is
- A.
20 N/C

- B.
5 N/C

- C.
500 N/C

- D.
250 N/C

- 20.The radius of a soap bubble whose potential is 16 Vis doubled. The new potential of the bubble will be
- A.
2 V

- B.
8 V

- C.
4 V

- D.
16 V

- 21.A hollow metal sphere of radius 5 cm is charged such that the potential on its surface is 10 V. The potential at a distance of 2 cm from the centre of the sphere
- A.
Zero

- B.
4 V

- C.
10 V

- D.
10/3 V

- 22.A radioactive source in the form of a metal sphere of radius 10
^{-2}m, emits beta particles at the rate of 5 x 10^{10}partiCles per sec. The source is electrically insulated. How long will it take for it's potential to be raised by 2 volts, assuming 40% of the emitted beta particles escape the source- A.
700 sec

- B.
700 μ sec

- C.
700 milli sec

- D.
700 n sec

- 23.A conducting sphere of radius R, and carrying a charge q is joined to a conducting sphere of radius 2R, and carrying a charge - 2q. The charge flowing between them will be
- A.
Q/3

- B.
Q

- C.
2q/3

- D.
4q/3

- 24.The solution of Laplace equation has no. of solutions for a given charge configuration
- A.
One

- B.
Two

- C.
More than two

- D.
Infinite

- 25.A sphere of radius r is placed concentrically inside a hollow sphere of radius R. The bigger and smaller spheres are given charges Q and q respectively and are insulated. The potential difference between the two .spheres depends on
- A.
Only charge q

- B.
Both q and Q

- C.
Only charge Q

- D.
None on q and Q