GATE 2026 EE – Question 34
Consider the circuit shown. Assume that the diode $D$ is ideal. The supply voltage $v_s=325\sin(2\pi50t)$ V, $L=500\ \mu$H, and $R=10\ \Omega$. The peak diode current (in amperes) is ____________.
(Round off to one decimal place)
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Correct answer: 32.34 to 32.66
Explanation
The circuit is a half-wave rectifier with an RL load. $\omega L=2\pi\cdot50\cdot500\times10^{-6}=0.157\ \Omega\ll R$, so $|Z|=\sqrt{10^2+0.157^2}\approx10.001\ \Omega$ and the phase lag is only $0.9^\circ$. The current is $i(t)=\dfrac{V_m}{|Z|}\left[\sin(\omega t-\phi)+\sin\phi\,e^{-Rt/L}\right]$; the time constant $L/R=50\ \mu$s is much smaller than the quarter period, so the transient has died out by the peak. The peak current is $\dfrac{325}{10.001}\approx32.5$ A.