According to lenz’s law, the direction of induced emf and hence current

A)     May be found by the right-hand rule

B)      Is always determined by the rate of cutting flux

C)      Always opposes the cause producing it

D)     Depends on whether the coil is wound with a right or left-hand spiral

Two infinite parallel metal plates are charged with equal surface charge density of the same polarity. The electric field in the gap between the plates is

A)     The same as that produced by one plate

B)      Double of the field produced by one plate

C)      Dependent on coordinates of field point

D)     Zero

Inside a hallow conducting sphere

A)     Electric field is zero

B)      Electric field is a non zero constant

C)      Electric field changes with the magnitude of the charge given to the conductor

D)     Electric field changes with distance from the centre of the sphere

Copper behaves as a

A)     Conductor always

B)      Conductor or dielectric depending on the applied electric field strength

C)      Conductor or dielectric depending on the frequency

D)     Conductor or dielectric depending on the electric current density

The depth of penetration of wave in a lossy dielectric increases with increasing

A)     Conductivity

B)      Permeability

C)      Wavelength

D)     Permittivity

The intrinsic impedance of copper at high frequencies is (GATE 1998)

A)     Purely resistive

B)      Purely inductive

C)      Complex with a capacitive component

D)     Complex with an inductive component

Explanation: The intrinsic impedance is given by √(jwµ√ϭ + jw€). Since copper is a good conductor, ϭ << jw€, thus the intrinsic impedance will have +j component only. This refers to complex with an inductive component.

When electromagnetic waves are propagated in a wave guide

A)     They travel along the border walls of the guide

B)      They are reflected from the walls but do not travel along them

C)      They travel through the dielectric without touching the walls

D)     They travel along all four walls of the wave guide

As a result of reflections from a plane conducting wall, electromagnetic waves acquire an apparent velocity greater than the velocity of light in space. This is called the

A)     Velocity of propagation

B)      Normal velocity

C)      Group velocity

D)     Phase velocity

Transmission of power to a load over transmission line achieves optimum value when standing-wave ration (SWR) becomes

A)     2:1

B)      1:2

C)      1:1

D)     1:4

White noise is that signal whose frequency spectrum

A)     Extends over infinite range

B)      Has flat spectral density

C)      Has spectral density varying as 1/f

D)     Has limited number of frequency components

The maximum space rate of the function which is increasing direction of the function is known as

1. curl of the vector function
2. gradient of the scalar function
3. divergence of the vector function
4. stokes theorem

Answer : gradient of the scalar function

The skin effect in a transmission line is affected by

1. The resistivity  of the transmission line
2. the current magnitude in the transmission line
3. the cross sectional area of the transmission line
4. the voltage applied across the transmission line

Answer : The cross sectional area of the transmission line

The equation of continuity defines the relation between

1. Electric field and magnetic field
2. Electric field and charge density
3. Flux density and charge density
4. Current density and charge density

Answer : Current density and charge density

The electrical field lines and equipotential lines

1. are parallel to each other
2. are one and the same
3. cut each other orthogonally
4. can be inclined to each other at any angle

Answer : Cut each other orthogonally

A quantitative relation between induced emf and rate of change of flux linkage is known as- (ESE 2013 Electrical Engineering Paper 1 (Objective)) -1

1. Maxwell's Law
2. Stoke's Law
3. Lenz's Law
4. Faraday's Law