WBJEE · Physics · Current Electricity
Two equal resistances, \(400 \Omega\) each, are connected in series with a \(8 \mathrm{V}\) battery. If the resistance of first one increases by \(0.5 \%\), the change required in the resistance of the second one in order to keep the potential difference across it unaltered is to
- A increase it by \(1 \Omega\)
- B increase it by \(2 \Omega\)
- C increase it by \(4 \Omega\)
- D decrease it by \(4 \Omega\)
Answer & Solution
Correct Answer
(B) increase it by \(2 \Omega\)
Step-by-step Solution
Detailed explanation
In series combination, \[ R=R_{1}+R_{2} \] Same current will pass in \(A_{1}\) and \(R_{2}\). According to question, \(R_{1}\) is increased by \(0.5 \%\) \(\therefore\) Increment in the resistance \[ \begin{array}{l} =\frac{0.5}{100} \times 400 \\ =2.0 \Omega \end{array} \] So…
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