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Assignment 01

Assignment - 1

For the given circuit, if the forward voltage drop for diode D₁ and D₂ are 0.7V and 0.3V, respectively, then which statement is true?
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a) Both diodes D₁ and D₂ are ON.
b) Diode D₁ is ON and D₂ is OFF.
c) Diode D₁ is OFF and D₂ is ON.
d) Both diodes D₁ and D₂ are OFF.

Note: The last date of submission is 12-09-25.

Solution:

To determine the states of the diodes (D1 and D2), we need to analyze the voltages across them and compare with their forward voltage drops.

Circuit Analysis:

  • Source voltage (V) = 10 V
  • R1 = 1 kΩ, R2 = 20 Ω
  • D1 forward voltage = 700 mV

  • D2 forward voltage = 300 mV

  • D1 (700 mV forward voltage):

  • The voltage across D1 will depend on the voltage divider formed by R1 and R2.

  • The voltage at the point where D1 is connected (let's call it V1) is determined by the voltage divider formula:

\[ V1 = V \times \frac{R2}{R1 + R2} \]

Substituting the values:

\[ V1 = 10 \times \frac{20}{1000 + 20} = 10 \times \frac{20}{1020} \approx 0.196 \, \text{V} = 196 \, \text{mV} \]

  • Since V1 = 196 mV is much less than the forward voltage of D1 (700 mV), D1 will be OFF.

  • D2 (300 mV forward voltage):

  • The voltage across D2 is the difference between the source voltage and the voltage at point V1, which is 10 V - 196 mV = 9.804 V.

  • Since 9.804 V is much higher than the forward voltage of D2 (300 mV), D2 will be ON.

Final Decision:

  • D1 is OFF.
  • D2 is ON.