Two `PN`-junction can be connected in series by three different methods as shown in the figure. If the potential difference in the junction is the same, then the correct connection will be

Options

A. In the circuit (1) and (2)
B. In the circuit (2) and (3)
C. In the circuit (1) and (3)
D. Only in the circuit (1)

Answer

B

Explanation

For series combination of cells, we join them as-, increase the e.m.f. If they are join like , then the net e.m.f. will be zero. p-n Junction is treated like a cell and hence the correct connection are shown in figures (2) and (3) p-n-p-n or n-p-n-p but p-n-n-p shown in circuit ( 1 ) is wrong.