CBSE 2024 · Region 3 · Set 1 · Q24 · 3 marks
A sinusoidal voltage is applied to an electric circuit containing a circuit element ' X ' in which the current leads the voltage by $\displaystyle \frac{\pi}{2}$.(a)Identify the circuit element ' X ' in the circuit.(b)Write the formula for its reactance.(c)Show graphically the variation of this reactance with frequency of ac voltage.(d)Explain the behaviour of this element when it is used in (i) an ac circuit, and (ii) a dc circuit.
A sinusoidal voltage is applied to an electric circuit containing a circuit element ' X ' in which the current leads the voltage by $\displaystyle \frac{\pi}{2}$.
(a)
Identify the circuit element ' X ' in the circuit.
(b)
Write the formula for its reactance.
(c)
Show graphically the variation of this reactance with frequency of ac voltage.
(d)
Explain the behaviour of this element when it is used in (i) an ac circuit, and (ii) a dc circuit.
Marking-scheme solution
(a) Identifying the element X
(b) Writing the formula for reactance
(c) Showing variation of reactance with frequency
(d) Explanation of behavior of element with
(i) an ac circuit
(ii) a dc circuit
(a) Capacitor
(b) \(\displaystyle \mathrm{X}_{c}=\frac{1}{\omega c}\)
Alternating CurrentAC Voltage Applied to a CapacitorUnderstandshort_answermedium
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CBSE Class 12 Physics past-paper question from the 2024board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.