A potential divider circuit is connected with a dc source of $20 V$ , a light emitting diode of glow in voltage $1.8 V$ and a zener diode of breakdown voltage of $3.2 V$ . The length (PR) of the resistive wire is $20 cm$ . The minimum length of PQ to just glow the LED is _____ $cm$

Question

Answer:

5

Solution:

$PR = 20 cm V_{PQ} = \frac{1}{4} \times R_{PR} ℓ_{m i n} (PQ) = \frac{1}{4} \times 20 = 5 cm$

TestHub · Accepted Answer

​ PR = 20 cm V PQ ​ = 4 1 ​ × R PR ​ ℓ m i n ​ ( PQ ) = 4 1 ​ × 20 = 5 cm ​

Physics - Semiconductors Question with Solution | TestHub

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