Practice free Alternating Current (Physics) NEET multiple-choice questions online with instant answers and detailed explanations. No login required.
A purely inductive circuit is an ideal circuit condition. In reality, inductors usually have:
The text mentions, 'Usually, inductors have appreciable resistance in their windings, but we shall assume that this inductor has negligible resistance' (for the purpose of an ideal purely inductive circuit analysis).
Which of the following describes the primary advantage of alternating current (AC) over direct current (DC) for electrical energy transmission and distribution?
The NCERT text states: 'The main reason for preferring use of ac voltage over dc voltage is that ac voltages can be easily and efficiently converted from one voltage to the other by means of transformers.'
In an AC circuit containing a resistor, what is the nature of electric energy dissipation?
The NCERT text mentions: 'Joule heating is given by $i^2R$ and depends on $i^2$ (which is always positive whether i is positive or negative) and not on i. Thus, there is Joule heating and dissipation of electrical energy when an ac current passes through a resistor.'
The RMS value of current ($I_{rms}$) in an AC circuit is defined such that it:
The NCERT text states: 'Joule heating is such a property, and there is one ampere of rms value of alternating current in a circuit if the current produces the same average heating effect as one ampere of dc current would produce under the same conditions.'
If the household line voltage is specified as 220 V, what does this value typically represent?
The NCERT text highlights, 'It is customary to measure and specify rms values for ac quantities. For example, the household line voltage of 220 V is an rms value...'
For a sinusoidal AC voltage $v = v_m \sin(\omega t)$, the RMS voltage ($V$) is given by:
According to the NCERT text, 'V = $v_m / \sqrt{2}$ = 0.707 $v_m$ (7.8)'.
Which of the following circuit elements dissipates energy in an AC circuit?
The NCERT text clarifies: 'There are no power losses associated with pure capacitances and pure inductances in an ac circuit. The only element that dissipates energy in an ac circuit is the resistive element.'
What is a 'phasor' in the context of AC circuits?
The NCERT text defines it: 'A phasor* is a vector which rotates about the origin with angular speed $\omega$, as shown in Fig. 7.4. The vertical components of phasors V and I represent the sinusoidally varying quantities v and i.'
In a purely capacitive AC circuit, what is the phase relationship between the current and the applied voltage?
The NCERT text states: 'The current through the capacitor is $\pi/2$ ahead of the applied voltage.' Also, 'Thus, we see that in the case of an inductor, the current lags the voltage by $\pi/2$ and in the case of a capacitor, the current leads the voltage by $\pi/2$.'
What is the average power supplied to a purely capacitive AC circuit over one complete cycle?
The NCERT text explicitly states: 'So, as in the case of an inductor, the average power $\overline{P_C} = \frac{1}{2}i_m v_m \left<\sin(2\omega t)\right> = 0$ since $\left<\sin(2\omega t)\right> = 0$ over a complete cycle.'
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The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.