In the circuit shown,if the forward voltage drop for the diode is $0.5\, V$,the current in the circuit will be.....$mA$.

The circuit shown in the figure contains two diodes,each with a forward resistance of $30 \, \Omega$ and infinite backward resistance. If the battery is $3 \, V$,the current through the $50 \, \Omega$ resistance (in ampere) is

Among the diodes shown in the following diagrams,which one is reverse biased?

$A$ $P-N$ junction diode is in forward bias with a current of $10 \ mA$. The potential drop across the diode is $0.5 \ V$. Assuming the current is independent of the potential,what is the maximum voltage of the battery in series with a $200 \ \Omega$ resistor to maintain this forward bias condition? (in $V$)

The figure shows a circuit in which three identical diodes are used. Each diode has a forward resistance of $20\,\Omega$ and an infinite backward resistance. Resistors $R_1 = R_2 = R_3 = 50\,\Omega$. The battery voltage is $6\,V$. The current through $R_3$ is.....$mA$.

What is a diode?