9
MCQ (Multiple Correct Answer)
When an electric field is applied across a semiconductor
A
electrons move from lower energy level to higher energy level in the conduction band
B
electrons move from higher energy level to lower energy level in the conduction band
C
holes in the valence band move from higher energy level to lower energy level
D
holes in the valence band move from lower energy level to higher energy level
10
MCQ (Multiple Correct Answer)
Consider an $n-p-n$ transitor with its base-emitter junction forward biased and collector base junction reverse biased. Which of the following statements are true?
A
Electrons crossover from emitter to collector
B
Holes move from base to collector
C
Electrons move from emitter to base
D
Electrons from emitter move out of base without going to the collector.
11
MCQ (Multiple Correct Answer)
Figure given below shows that transfer characteristics of a base biased CE transistor. Which of the following statements are true?
A
At $V_i=0.4 \mathrm{~V}$, transistor is in active state
B
At $V_i=1 \mathrm{~V}$, it can be used as an amplifier
C
At $V_i=0.5 \mathrm{~V}$, it can be used as a switch turned off
D
At $V_i=2.5 \mathrm{~V}$, can be used as a switch turned on
12
MCQ (Multiple Correct Answer)
In a $n-p-n$ transistor circuit, the collector current is 10 mA . If 95 per cent of the electrons emitted reach the collector, which of the following statements are true?
A
The emitter current will be 8 mA
B
The emitter current will be 10.53 mA
C
The base current will be 0.53 mA
D
The base current will be 2 mA
13
MCQ (Multiple Correct Answer)
In the depletion region of a diode
A
there are no mobile charges
B
equal number of holes and elections exist, making the region neutral
C
recombination of holes and electrons has taken place
D
immobile charged ions exist