JEE Mains · Physics · STD 12 - 3. current electricity
In the given circuit the internal resistance of the \(18\,V\) cell is negligible. If \(R_1 = 400 \,\Omega ,\,R_3 = 100\,\Omega \) and \(R_4 = 500\,\Omega \) and the reading of an ideal voltmeter across \(R_4\) is \(5\,V,\) then the value of \(R_2\) will be ........... \(\Omega\)
- A \(300\)
- B \(450\)
- C \(550\)
- D \(230\)
Answer & Solution
Correct Answer
(A) \(300\)
Step-by-step Solution
Detailed explanation
\(\frac{12}{400}=\frac{6}{600}+\frac{6}{R_{2}}\) \(\Rightarrow \quad \frac{1}{200}=\frac{1}{600}+\frac{1}{R_{2}}\) \(\Rightarrow \quad \mathrm{R}_{2}=300\, \Omega\)
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