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Current Electricity — Physics STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 SciencePhysicsCurrent Electricity1 Mark
MCQ
For two statements are given$-$one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Two electric bulbs of $50$ and $100$ watt are given. When connected in series $50$ watt bulb glows more but when connected in parallel $100$ watt bulb glows more.
Reason: In series combination, power is directly proportional to the resistance of circuit. But in parallel combination, power is inversely proportional to the resistance of the circuit.
  • ✓
    Both $A$ and $R$ are true, and $R$ is the correct explanation of $A.$
  • B
    Both $A$ and $R$ are true, but $R$ is not the correct explanation of $A.$
  • C
    $A$ is true, but $R$ is false.
  • D
    $A$ is false, and $R$ is also false.
✓

Answer

Correct option: A.
Both $A$ and $R$ are true, and $R$ is the correct explanation of $A.$
Resistance of $50$ watt bulb is two times the resistance of $100$ watt bulb. When bulbs are connected in series, $50$ watt bulb will glow more as $P = i^2R ($current remains same in series$).$ ln parallel, the $100$ watt bulb will glow more as $\text{P}=\frac{\text{V}^2}{\text{R}} ($ potential difference remain same in parallel $).$

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