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 V_i is 20 V, V_BE = 0 and V_CE = 0. The values of I_B, I_C and β are given by

• I_B = 40 μA, I_C = 10 mA, β = 250

• I_B = 25 μA, I_C = 5 mA, β = 200

• I_B = 40 μA, I_C = 5 mA, β = 125

• I_B = 20 μA, I_C = 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

The following circuit represents

• OR gate

• XOR gate

• AND gate

• NAND gate

 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

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

• $2\times {10}^8$

• 20

• 50

• 40

In junction diode, the holes are because of

• Missing electrons

• extra electrons

• protons

• neutrons

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