Question

Diode and resistance are connected as shown. Which statement is TRUE?

• A. Diode $D_1$ and diode $D_2$ both are forward biased.
• B. Diode $D_1$ and diode $D_2$ both are reverse biased.
• C. Diode $D_1$ is forward biased and diode $D_2$ is reverse biased.
• D. Diode $D_1$ is reverse biased and diode $D_2$ is forward biased.

Hint:

Shortcut: Compare voltages: Anode > Cathode → Forward bias Anode < Cathode → Reverse bias

Answer 1

The Correct Option is C

Concept: A diode is:
• Forward biased if anode is at higher potential than cathode
• Reverse biased if anode is at lower potential than cathode (The triangle side is anode, vertical line is cathode)

Step 1: Analyze Fig (1)
Left side = $0\,V$, right side = $-4\,V$ \[ \text{Anode at } 0V,\quad \text{Cathode towards } -4V \] Since: \[ 0V > -4V \] \[ \Rightarrow D_1 \text{ is forward biased} \]

Step 2: Analyze Fig (2)
Left side = $-5\,V$, right side = $-3\,V$ \[ \text{Anode at } -5V,\quad \text{Cathode towards } -3V \] Since: \[ -5V < -3V \] \[ \Rightarrow D_2 \text{ is reverse biased} \] Conclusion:
$D_1$ is forward biased and $D_2$ is reverse biased. Final Answer: Option (C)