In the combination of the following gates the output Y can be written in terms of inputs A and B as
In the circuit shown in the figure, the input voltage Vi is 20 V, VBE = 0 and VCE = 0. The values of IB, IC and β are given by
IB = 40 μA, IC = 10 mA, β = 250
IB = 25 μA, IC = 5 mA, β = 200
IB = 40 μA, IC = 5 mA, β = 125
IB = 20 μA, IC = 5 mA, β = 250
In a p-n junction diode, change in temperature due to heating
Affects only reverse resistance
Affects only forward resistance
Affects the overall V - I characteristics of p-n junction
Does not affect resistance of p-n junction
In forward biased if the p-n junctions diode is forward biased, then width of potential barrier in p-n junction diode
remains constant
increase
decrease
None of these
C.
decrease
In forward bias the terminal of the same polarities are connected between the diode and the supply. Hence by repulsion excess number of holes or electron come out and width of potential barrier can be decreased.
The slope of plate characteristic and mutual characteristic curves of a triode valve is 0.02 mA / V and 1 mA / V. The amplification factor of triode valve is
20
50
40
In the CB mode of a transistor, when the collector voltage is changed by 0.5 volt, the collector current changes by 0.05 mA. The output resistance will be
10 kΩ
20 kΩ
5 kΩ
2.5 kΩ
The amplification factor of a triode valve is 15. If the grid voltage is changed by 0.3 V, the change in plate voltage in order to keep the current constant (in volt) is :
0.02
0.002
4.5
5.0
Zener diode is used for
producing oscillations in an oscillator
amplification
stabilisation
rectification