CBSE
A light emitting diode (LED) has a voltage drop of 2 volt across it and passes a current of 10 mA when it operates with a 6 volt battery through a limiting resistor R. The value of R is
40 kΩ
4 kΩ
200 kΩ
400 kΩ
An amplifier has a voltage gain Av = 1000. The voltage gain in dB is
30 dB
60 dB
3 dB
20 dB
In the half wave rectifier circuit operating from 50 Hz mains frequency, the fundamental frequency in the ripple would be
25 Hz
50 Hz
70.7 Hz
100 Hz
A transistor is a/an
chip
insulator
semiconductor
metal
When a p-n diode is reverse biased,then
no current flows
the depletion region is increased
the depletion region is reduced
the height of the potential barrier is reduced
The number 0 (zero) is required for
transistor
abacus
computer
calculator
The minimum potential difference between the base and emitter required to switched a silicon transistor ON is approximately
1 V
3 V
5 V
4.2 V
In communication with help of antenna if height is dobled then the range covered which was initially r would become
3r
4r
5r
Zener diode acts as a/an
oscillator
regulator
rectifier
filter
The circuit given below represents which of logic operations?
AND
NOT
OR
NOR