JEE Main & Advanced
JEE Main Paper (Held on 12-4-2019 Afternoon)
question_answer
Figure shown a DC voltage regulator circuit, with a Zener diode of breakdown voltage = 6V. If the unregulated input voltage varies between 10 V to 16 V, then what is the maximum Zener current? [JEE Main 12-4-2019 Afternoon]
A)2.5 mA
B)3.5 Ma
C)7.5 mA
D)1.5 mA
Correct Answer:
B
Solution :
Maximum current will flow from zener if input voltage is maximum. When zener diode works in breakdown state, voltage across the zener will remain same. \[\therefore \]\[{{V}_{across4k\Omega }}=64\] \[\therefore \]Current through\[4K\Omega =\frac{6}{4000}A=\frac{6}{4}mA\] Since input voltage = 16V \[\therefore \]Potential difference across \[2K\Omega =10V\] \[\therefore \] Current through \[2k\Omega =\frac{10}{2000}=5mA\] \[\therefore \] Current through zener diode \[=({{I}_{S}}-{{I}_{L}})=3.5mA\]