List of top Physics Questions on Semiconductor electronics: materials, devices and simple circuits asked in JEE Main

An $n-p-n$ transistor has three leads $A, B$ and $C$. Connecting $B$ and $C$ by moist fingers, $A$ to the positive lead of an ammeter, and $C$ to the negative lead of the ammeter, one finds large deflection. Then, $A, B$ and $C$ refer respectively to :

A Zener diode is connected to a battery and a load as shown below : The currents $I, I_z$ and $I_L$ are respectively

Figure shows a circuit in which three identical diodes are used. Each diode has forward resistance of $20 \,\Omega$ and infinite backward resistance. Resistors $R_{1}=R_{2}=R_{3}=50\,\Omega$. Battery voltage is $6\, V$. The current through $R_3$ is:

Which of the following is metal compound semiconductor?