EXERCISE 21

An $n-p-n$ transistor power amplifier is $CE$ configuration gives

The input resistance of a silicon transistor is $100\Omega .$ Base current is changed by $40\mu \mathrm{A},$ which results in a change in collector current by $2 \mathrm{mA}.$ The transistor is used as common emitter amplifier with a load resistance of $4\mathrm{k}\Omega .$ The voltage gain of the amplifier is

The output of an OR gate is connected to both the inputs of a NAND gate. The combination will serve as a

The output of given logic circuit is Fig.21.97 is

Which type of gate the following truth table represents?

Truth table for system of four NAND gates as shown in Fig.21.99 is

For the logic circuit given in Fig.21.100, the outputs $Y$ for $A=0, B=0$ and $A=1, B=1$ are

To get an output $\mathrm{Y}=1$ in given circuit in Fig.21.101 which of the following input will be correct :