Question

In Thevenin's theorem, if a circuit has \(V_{th}=20\,\mathrm{V}\), \(R_{th}=4\,\Omega\), then the load current for \(R_L=4\,\Omega\) is

• A. \(2.5\,\mathrm{A}\)
• B. \(5\,\mathrm{A}\)
• C. \(10\,\mathrm{A}\)
• D. \(20\,\mathrm{A}\)

Hint:

For a Thevenin equivalent, \[ \boxed{ I_L=\frac{V_{th}}{R_{th}+R_L} } \] where \(R_{th}\) and \(R_L\) are connected in series.

Answer 1

The Correct Option is A

Step 1: Use Thevenin equivalent circuit. The load current is \[ I_L = \frac{V_{th}}{R_{th}+R_L}. \] Given, \[ V_{th}=20\,\mathrm{V},\qquad R_{th}=4\,\Omega,\qquad R_L=4\,\Omega. \]

Step 2: Calculate the load current. \[ I_L = \frac{20}{4+4} = \frac{20}{8} = 2.5\,\mathrm{A}. \] Hence, \[ \boxed{2.5\,\mathrm{A}} \] Therefore, \[ \boxed{(A)} \] is the correct answer.