Question

If each diode in figure has forward bias resistance of $$ 25 \Omega $$ and infinite resistance in reverse bias , what will be the value of current $$ I_1 , I_2 , I_3 $$ and $$ I_4 $$ ?

Answer 1

$$ I_3 $$ is zero as the diode in that branch is reverse biased. Resistance in the branch AB and EF are each $$ (125 + 25)\Omega = 150 \Omega $$

As AB and EF are identical parallel branches , their effective resistance is $$ \dfrac{150}{2} = 75 \Omega $$

$$ \therefore \, $$ Net resistance in the circuit = $$ (75 + 25) \Omega = 100 \, \Omega $$

$$ \therefore \, $$ Current $$ I_1 = \dfrac{5}{100} = 0.05 \,A $$

AS resistance of AB and EF are equal and $$ I_1 = I_2 + I_3 + I_4 , I_3 = 0 $$

$$ \therefore \, I_2 = I_4 = \dfrac{0.05}{2} = 0.025\,A $$