If a full wave rectifier circuit is operating from 50 Hz mains, the fundamental frequency in the ripple will be

A diode having potential difference 0.5 V across its junction which does not depend on current, is connected in series with resistance of 20 $\mathrm{\Omega }$ across source. If 0.1 A passes through resistance then what is the voltage of the source

When NPN transistor is used as an amplifier

The phase difference between input and output voltages of a CE circuit is 

If $\mathrm{\alpha }$ = 0.98 and current through emitter ${\mathrm{i}}_{\mathrm{e}}$ = 20 mA, the value of $\mathrm{\beta }$ is 

In a PNP transistor working as a common-base amplifier, current gain is 0.96 and emitter current is 7.2 mA. The base current is:

 If ${\mathrm{l}}_1$, ${\mathrm{l}}_2$, ${\mathrm{l}}_3$ are the lengths of the emitter, base and collector of a transistor then 

In an NPN transistor circuit, the collector current is 10 mA. If 90% of the electrons emitted reach the collector, the emitter current (${\mathrm{i}}_{\mathrm{E}}$) and base current (${\mathrm{i}}_{\mathrm{B}}$) are given by 

In a common emitter transistor, the current gain is 80. What is the change in collector current, when the change in base current is 250 $\mathrm{\mu }$A 

Least doped region in a transistor 

The transistors provide good power amplification when they are used in 

The transfer ratio of a transistor is 50. The input resistance of the transistor when used in the common-emitter configuration is 1 K$\mathrm{\Omega }$. The peak value for an A.C input voltage of 0.01 V peak is 

For a transistor the parameter $\mathrm{\beta }$ = 99. The value of the parameter $\mathrm{\alpha }$ is

In a PNP transistor the base is the N-region. Its width relative to the P-region is 

A common emitter amplifier is designed with NPN transistor ($\mathrm{\alpha }$ = 0.99). The input impedance is 1 K$\mathrm{\Omega }$ and load is 10 K$\mathrm{\Omega }$. The voltage gain will be:

The symbol given in figure represents 

The most commonly used material for making transistor is

An NPN-transistor circuit is arranged as shown in figure. It is
 

For a transistor, the current amplification factor is 0.8 when it is connected in the common base configuration. The transistor is now connected in common emitter configuration. The change in the collector current when the base current changes by 6 mA, is :

In a common base amplifier circuit, calculate the change in base current if that in the emitter current is 2 mA and $\mathrm{\alpha }$ = 0.98

In a transistor circuit shown here the base current is 35 $\mu$A. The value of the resistor Rb is

For a transistor, in a common emitter arrangement, the alternating current gain $\mathrm{\beta }$ is given by

The relation between $\mathrm{\alpha }$ and $\mathrm{\beta }$ parameters of current gains for a transistors is given by

In the CB mode of a transistor, when the collector emitter voltage is changed by 0.5 volt. The collector current changes by 0.05 mA. The output resistance will be 

Consider an NPN transistor amplifier in the common-emitter configuration. The current gain of the transistor is 100. If the collector current changes by 1 mA, what will be the change in emitter current?

In a common base amplifier the phase difference between the input signal voltage and the output voltage is

In NPN transistor the collector current is 10 mA. If 90% of electrons emitted reach the collector, then

In a transistor in CE configuration, the ratio of power gain to voltage gain is 

The XOR gate and NOR gate respectively are 

Given below are symbols for some logic gates

Given below are four logic gate symbol (figure). Those for OR, NOR and NAND are respectively