Electronics and Communication Engineering - Electronic Devices and Circuits

41.
The drain characteristics of JFET in operating region, are
inclined upwards
almost flat
inclined downwards
inclined upwards or downwards
Answer: Option
Explanation:

The drain current is almost constant. Therefore, characteristics is flat.


42.
As temperature increases
the forbidden energy gap in silicon and germanium increase
the forbidden energy gap in silicon and germanium decrease
the forbidden energy gap in silicon decreases while that in germanium decreases
the forbidden energy gap in silicon increases while that in germanium decreases
Answer: Option
Explanation:

Therefore, conductivity increases.


43.
When a reverse bias is applied to a p-n junction, the width of depletion layer.
decreases
increases
remains the same
may increase or decrease
Answer: Option
Explanation:

Therefore, the resistance is very high.


44.
The Hall constant in Si bar is given by 5 x 103 cm3/ coulomb, the hole concentration in the bar is given by
105/cm3
1.25 x 1015/cm3
1.5 x 1015/cm3
1.6 x 1015/cm3
Answer: Option
Explanation:

.


45.
Which of the following devices has a silicon dioxide layer?
NPN transistor
Tunnel diode
JFET
MOSFET
Answer: Option
Explanation:

The SiO2 layer provides very high input impedance.