CBSE
Multiple Choice QuestionsA transistor is connected in CE configuration. The supply to the collector is 8 V and the voltage drop across a resistor of 400 Ω in the collector circuit is 0.5 V. If the current gain factor is = 0.96 then, the base current will be nearly
52 µA
42 µA
32 µA
26 µA
The width of depletion layer in a p-n junction diode
increases when a forward bias is applied
increases when a reverse bias is applied
decreases when a reverse bias is applied
remains same irrespective of bias voltage
Which of the following truth table is of NAND gate ?
To get an output y = 1 from the circuit shown the inputs A, B and C must be respectively.
0, 1, 0
1, 0, 0
1, 0, 1
1, 1, 0
In a common emitter (CE) amplifier having a voltage gain G, the transistor used has transconductance 0.03 mho and current gain 25. If the above transistor is replaced with another one with transconductance 0.02 mhoand current gain 20, the voltage gain will be
1.5 G
A p-n-p transistor is used in common-emitter mode in an amplifier circuit. A change of 45 µA in the base current brings a change of 3 mA in collector current and 0.05 V in base-emitter voltage. If a load of 7 kΩ is used, then voltage gain of amplifier is
729.25
824.41
236.34
424.27
A Zener diode, having breakdown voltage equal to 15 V, is used in a voltage regulator circuit shown in figure. The current through the diode is
5 mA
10 mA
15 mA
20 mA
In the following circuit, the output Y becomes one for the inputs
A= 0, B = 1, C = 0
A = 1, B = 1, C = 0
A =1, B= 1, C = 1
A = 1, B= 0, C = 1
Carbon, silicon and germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy band gaps represented by (Eg)C , (Eg )Si , and (Eg)Ge respectively. Which one of the following relationships is true in their case ?
(Eg)C > (Eg)Si
(Eg)C = (Eg)Si
(Eg)C < (Eg)Ge
(Eg)C < (Eg)Si
Then n-type semiconductors are obtained, when germanium is doped with
arsenic
phosphorus
antimony
any one of these
