Question 11.C-A.71: Calculate the current through the following circuits. (The d...

(a) In the circuit, the diode D_{1} is reverse biased and diode D_{2} is forward based. Current flows through the diode D_{2}. So the resistors 5 Ω and 10 Ω are in series. The effective resistance R = R_{1} + R_{2} = 10 + 5 = 15 Ω

Voltage V = 30 V

Current  I =\frac{V}{R}=\frac{30}{15}=2 A

(b) Here the diode D_{1} and D_{2} are forward biased. The current flows through D_{1} and D_{2}. Here the resistors 10 Ω and 10 Ω are in parallel, so the effective resistance

This resistor is in series with 5 Ω resistor. so effective resistance

R = 5 + 5 = 10 Ω

Voltage = 30 V

Current   = I =\frac{V}{R}=\frac{30}{10}=3 A