Find the current $I$ in the circuit in $amp$.

In the given figure,each diode has a forward bias resistance of $30\, \Omega$ and infinite resistance in reverse bias. The current ${I}_{1}$ will be $....\,A$.

If the internal resistance of the cell is negligible,then the current flowing through the circuit is: (in $A$)

The $I-V$ characteristics of a $p-n$ junction diode in forward bias is shown in the figure. The ratio of dynamic resistance,corresponding to forward bias voltages of $2 \; V$ and $4 \; V$ respectively,is

In the following circuit,$PN$-junction diodes $D_1$,$D_2$,and $D_3$ are ideal. For the following potentials of $A$ and $B$,the correct increasing order of equivalent resistance between $A$ and $B$ will be:
$(i) V_A = -10 V, V_B = -5 V$
$(ii) V_A = -5 V, V_B = -10 V$
$(iii) V_A = -4 V, V_B = -12 V$

Currents flowing in each of the following circuits $A$ and $B$ respectively are