JEE Mains · Physics · STD 12 -7. Alternating current
A resistance of \(40 \,\Omega\) is connected to a source of alternating current rated \(220\, V , 50 Hz\). Find the time taken by the current to change from its maximum value to \(ms\) value
- A \(2.5\, ms\)
- B \(1.25\, ms\)
- C \(2.5 \,s\)
- D \(0.25 \,s\)
Answer & Solution
Correct Answer
(A) \(2.5\, ms\)
Step-by-step Solution
Detailed explanation
Considering sinusoidal \(AC\). Phase at maximum value \(=\frac{\pi}{2}\) Phase at rms value \(=\frac{3 \pi}{4}\) Thus phase change \(=\frac{3 \pi}{4}-\frac{\pi}{2}=\frac{\pi}{4}\) \(Now \,\omega=2 \pi f\) \(=2 \pi \times 50\) \(=100 \pi\) time taken…
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