# Electromagnetic Theory [GATE (Graduate Aptitude Test in Engineering) Physics]: Questions 55 - 60 of 88

Access detailed explanations (illustrated with images and videos) to 659 questions. Access all new questions- tracking exam pattern and syllabus. View the complete topic-wise distribution of questions. Unlimited Access, Unlimited Time, on Unlimited Devices!

View Sample Explanation or View Features.

Rs. 450.00 -OR-

## Question 55

Appeared in Year: 2008

### Question

MCQ▾

At time , a charge distribution exists within an ideal homogeneous conductor of permittivity and conductivity . At a later time is given by –

### Choices

Choice (4)Response

a.

b.

c.

d.

## Question 56

Electromagnetic Theory

Appeared in Year: 2008

### Question

MCQ▾

The curl of a vector field is . Identify the appropriate vector field from the choices given below.

### Choices

Choice (4)Response

a.

b.

c.

d.

## Question 57

Appeared in Year: 2007

### Question

MCQ▾

A toroidal coil has N closely – wound turns. Assume the current through the coil to be and the toroid is filled with a magnetic material of relative permittivity . The magnitude of magnetic induction inside the toroid, at a radial distance from the axis, is given by –

### Choices

Choice (4)Response

a.

b.

c.

d.

### Passage

The Fresnel relation between the amplitudes of incident and reflected electromagnetic waves at an interface between air and a dielectric of reflective index , are –

The subscripts and refer to polarization, parallel and normal to the plane of incidence respectively. Here, and are the angles of incidence and refraction respectively.

## Question 58 (1 of 2 Based on Passage)

Appeared in Year: 2007

### Question

MCQ▾

The condition for the reflected ray to be completely polarized is –

### Choices

Choice (4)Response

a.

b.

c.

d.

## Question 59 (2 of 2 Based on Passage)

Appeared in Year: 2007

### Question

MCQ▾

For normal incidence at an air – glass interface with the fraction of energy reflected is given by –

### Choices

Choice (4)Response

a.

0.16

b.

0.04

c.

0.40

d.

0.20

## Question 60

Electromagnetic Theory

Appeared in Year: 2007

### Question

MCQ▾

The electromagnetic field due to a point charge must be described by Lienard Wiechert potentials when –

### Choices

Choice (4)Response

a.

The electric and magnetic field are not perpendicular

b.

The calculation is done for the radiation zone, i.e.. far away from the charge

c.

The point charge is highly accelerated

d.

The point charge is moving with velocity close to that of light

Developed by: