JEE Main 2026 · 5 Apr · Shift 2 · Physics Q45

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PhysicsSingle correct+4 / -1Question 45 of 75

In a semiconductor p-n diode, the doping concentrations on p-side and n-side are $10^{15}$ atoms/cm³ and $10^{18}$ atoms/cm³, respectively. Which one of the following statements is true ?

Widths of depletion region on either side of the interface are equal

The depletion region width is more on p-side compared to that in n-side

The depletion region width is more on n-side compared to that in p-side

No depletion region forms because of unequal doping concentrations on p and n-sides

Answer and worked solution

Official answer: B

Charge balance. The depletion layer has equal charge on each side: $N_Ax_p=N_Dx_n$ .

Lightly doped side. The p-side has $10^{15}$ per cm³ against $10^{18}$ on the n-side, so the region extends about 1000 times further into the p-side.

(B)

Topics:Semiconductors and p-n junction

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JEE Main 2026 · 5 Apr · Shift 2, Physics question 45