Question 84 of 209

When a diode is forward biased, it has a voltage drop of $0.5V$ . the safe limit of current through the diode is $10mA$. If a battery of emf $1.5V$ is used in the circuit, the value of minimum resistance to be connected in series with the diode so that the current does not exceed the safe limit is :

A$300\Omega$B$50\Omega$C$100\Omega$D$200\Omega$

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Answer: (C) $100\Omega$

${V}_{diode}=0.5volt$
${V}_{R}=1.5-0.5=1volt$
$iR=1$
$R=\dfrac{1}{i}=\dfrac{1}{{10}^{-2}}=100\Omega$