There will be questions related to Electromagnetics in every GATE paper. Electromagnetics is one such subject where primary focus should be on understanding Maxwell’s equations(Concepts, forms and different types of problems). One should have thorough understanding of vector calculus and integration to come out on top. Try to get the below questions right. More questions will follow in future posts.

1) An electron traveling horizontally enters a region where a uniform electric field is

directed upward. What is the direction of the force exerted on the electron once it

entered the field?

(a) To the left

(b) To the right

(c) Upward

(d) Downward

Ans: d

2) Point charges 30 nC, -20 nC, and 10 nC are located at (-1,0,2), (0,0,0), and (1,5,-1)

respectively. The total flux leaving a cube of side 6 m centered at the origin.

(a) -20 nC

(b) 10 nC

(c) 20 nC

(d) 60 nC

Ans : b

3) Plane z = 10 m carries charge 20 nC/m2 . The electric field intensity at the origin

is

(a) -10 ˆaz V/m

(b) -18π aˆz V/m

(c) -72π aˆz V/m

(d) -360π aˆz V/m

Ans : d

4) Consider the following cases:

• A point charge Q is placed at the origin. Let D1 be the flux due to this charge

over a sphere of radius b centered at the origin.

• A uniformly charged sphere of radius a(a<b) centered at the origin with a

total charge of Q. Let D2 be the flux due to this over a sphere of radius b

centered at the origin is.

Which of the following is true

(a) D1 = D2

(b) D1 is not equal to D2

(c) Under special conditions, D1 = D2

Ans: a

5) Two identical coaxial circular coils carry the same current I but in opposite directions.

The magnitude of the magnetic field −→B at a point on the axis midway

between the coil is

(a) Zero

(b) The same as that produces by one coil

(c) Twice that produced by one coil

(d) Half that produced by one coil

Ans: a

6) According to Ampere’s Law, the path integral around the closed loop C is

given by

(a) µ0(I1 + I2 − I3)

(b) µ0(−I1 − I2 + I3)

(c) µ0(I1 + I2 + I3)

(d) −µ0(I1 + I2 + I3)

For any explanations , use comment section.