IndiaBIX

Electronics and Communication Engineering - Electromagnetic Field Theory

Exercise : Electromagnetic Field Theory - Section 2
11.
The threshold voltage of an n-channel enhancement mode MOSFET is 0.5 when the device is biased at a gate voltage of 3V. Pinch off would occur at a drain voltage of
1.5 V
2.5 V
3.5 V
4.5 V
Answer: Option
Explanation:

It is used with reverse bias.

12.
Which of these has degenerate p and n materials?
Zener diode
PIN diode
Tunnel diode
Photo diode
Answer: Option
Explanation:

Tunnel diode has heavily doped p and n layers called degenerate p and n materials.

13.
A Schottky diode clamp is used along with switching BJT for
reducing the power dissipation
reducing the switching time
increasing the value of β
reducing the base current
Answer: Option
Explanation:

Schottky diode has very low switching time.

14.
From the given circuit below, we can conclude that.
BJT is pnp
BJT is npn
transistor is faulty
not possible to determined
Answer: Option
Explanation:

According to figure, both the LED is glowing, which indicate that circuit is complete in both the half cycle of a.c. signal.

Therefore Emitter and Base junction will act as short circuit in both direction, which indicate transistor is faulty.

15.
In a piezoelectric crystal, applications of a mechanical stress would produce
plastic deformation of the crystal
magnetic dipoles in the crystal
electrical polarization in the crystal
shift in the Fermi level
Answer: Option
Explanation:

In piezoelectric materials mechanical stress produces electric polarization.

Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers