When npn transistor is used as amplifier
electrons move from base to collector
holes move from emitter to base
electrons move from collector to base
electrons move from collector to base
For a transistor amplifier in common emitter configuration having load impedance of 1 kΩ (hfe = 50 and hoe = 25) the current gain is
-5.2
-15.7
-24.8
-24.8
A piece of copper and another of germanium are cooled from room temperature to 77 K, the resistance of
each of them increases
each of them decreases
copper decreases and germanium increases
copper decreases and germanium increases
D.
copper decreases and germanium increases
Copper is metallic conductor and germanium is semiconductor therefore as temperature decreases resistance of good conductor decreases while for semiconductor it increases.
The manifestation of band structure in solids is due to
Heisenberg’s uncertainty principle
Pauli’s exclusion principle
Bohr’s correspondence principle
Bohr’s correspondence principle
When p-n junction diode is forward biased
the depletion region is reduced and barrier height is increased
the depletion region is widened and barrier height is reduced.
both the depletion region and barrier height reducedboth the depletion region and barrier height reduced
both the depletion region and barrier height reducedboth the depletion region and barrier height reduced