# ECE MCQ's and doubts.

To discuss questions related to various subjects of ECE. Helpful in all technical exams like gate, ies, Bsnl jto. Sail, bel, etc.

Along with this, a new feature "Concept card" is introduced to build up small concepts that would be helpful in technical interviews.

Bsnl jto 2009

Bsnl jto-2009

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Mechanical impedance is the ratio of

• none
• rms force to rms velocity
• rms velocity to rms displacement
• rms force to rms displacement

0 voters

The input impedance of short-circuited line of length l where λ/4 l < λ/2, is

• capacitive
• resistive
• inductive
• none

0 voters

A rectangular metal waveguide filled with a dielectric of relative permittivity εr = 4, has the inside dimensions 3 x 1.2 cm, the cut off frequency for the dominant mode is

A.2.5 GHz B.5 GHz C.10 GHz D.12.5 GHz

For F1 layer the maximum ionic density is 2.3 x 104 electrons per cc. The critical frequency for this layer will be

A.1.36 MHz

B.13.6 MHz

C.136 MHz

D.1360 MHz

The velocity of electromagnetic wave in a good conductor is

A.3 x 108 m/s

B.more than 3 x 108 m/s

C.very low

D.high

To increase Q factor of a coil, the wire should be

• long and thin
• long
• thick
• thin

0 voters

An RLC series circuit is underdamped. To make it overdamped, the value of R

• has to be reduced to zero
• has to be increased to infinity
• has to be decreased
• has to be increased

0 voters

The terms RMS and average values apply only to sine waves.

• true
• false

0 voters

The drift velocity of electrons is

• D.half the speed of light
• A.very small as compared to speed of light
• B.equal to speed of light
• C.almost equal to speed of light

0 voters

..

Ies 2012

Ies 2011

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With increase in temperature the fermi level in an intrinsic semiconductor

• Remains at the centre of forbidden gap
• Moves into conduction band
• Moves closer to valence band edge
• Moves closer to conduction band edge

0 voters

Answer given in book is d..how

I m an student of ece. I want to ask that in barc oces will there be any questions about computer architech in ece paper?????