back to directory
NEET PHYSICSALTERNATING CURRENTEasy

Question

A small-signal voltage V(t)=V0sin⁡(ωt)V(t) = V_0 \sin(\omega t) is applied across an ideal capacitor C:

A

over a full cycle, the capacitor C does not consume any energy from the voltage source

B

current I(t) is in phase with voltage V(t)

C

current I(t) leads voltage V(t) by 180°

D

current I(t) lags voltage V(t) by 90°

Step-by-Step Solution

In an AC circuit containing only an ideal capacitor, the current I(t)I(t) leads the voltage V(t)V(t) by a phase angle of π/2\pi/2 or 90∘90^\circ . This eliminates options suggesting they are in phase, lead by 180°, or lag. The average power consumed over a full cycle is P=VrmsIrmscos⁡ϕP = V_{rms}I_{rms} \cos \phi. Since the phase difference ϕ=90∘\phi = 90^\circ, the power factor cos⁡ϕ=0\cos \phi = 0, meaning the average power consumed is zero. The capacitor stores energy during one part of the cycle and returns it to the source in the next.

Exam Context & Concepts Covered

This question aligns with the NEET PHYSICS syllabus, specifically targeting concepts from ALTERNATING CURRENT. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

PHYSICSALTERNATING CURRENTsmallsignalvoltagesinomegaappliedacross

More ALTERNATING CURRENT Questions

View all

In an alternating current circuit consisting of elements in series, the current increases on increasing the frequency of the supply. Which of the following elements are likely to constitute the circuit? (a) Only resistor (b) Resistor and an inductor (c) Resistor and a capacitor (d) Only a capacitor

A.(b), (c)
B.(a), (d)
C.(b), (d)
D.(c), (d)
MediumSolve

An AC source given by $V = V_m \sin(\omega t)$ is connected to a pure inductor $L$ in a circuit and $I_m$ is the peak value of the AC current. The instantaneous power supplied to the inductor is:

A.$\frac{V_m I_m}{2} \sin(2\omega t)$
B.$-\frac{V_m I_m}{2} \sin(2\omega t)$
C.$V_m I_m \sin^2(\omega t)$
D.$-V_m I_m \sin^2(\omega t)$
MediumSolve

A transformer having efficiency of 90% is working on 200 V and 3 kW power supply. If the current in the secondary coil is 6A, the voltage across the secondary coil and the current in the primary coil respectively are:

A.300 V, 15 A
B.450 V, 15 A
C.450 V, 13.5 A
D.600 V, 15 A
MediumSolve

A standard filament lamp consumes 100 W when connected to a 200 V AC mains supply. The peak current through the bulb will be:

A.0.707 A
B.1 A
C.1.414 A
D.2 A
EasySolve

The net impedance of the circuit (as shown in the figure) will be:

A.25 $\Omega$
B.$10\sqrt{2} \ \Omega$
C.15 $\Omega$
D.$5\sqrt{5} \ \Omega$
MediumSolve

A 12 V, 60 W lamp is connected to the secondary of a step-down transformer, whose primary is connected to AC mains of 220 V. Assuming the transformer to be ideal, what is the current in the primary winding?

A.0.37 A
B.0.27 A
C.2.7 A
D.3.7 A
EasySolve

The variation of EMF with time for four types of generators is shown in the figures. Which amongst them can be called AC voltage?

A.(a) and (d)
B.(a), (b), (c), and (d)
C.(a) and (b)
D.only (a)
EasySolve

An inductor of inductance L, a capacitor of capacitance C and a resistor of resistance R are connected in series to an AC source of potential difference V volts. The potential difference across L, C and R is 40 V, 10 V and 40 V, respectively. The amplitude of the current flowing through the LCR series circuit is $10\sqrt{2}$ A. The impedance of the circuit will be:

A.4 $\Omega$
B.5 $\Omega$
C.$4\sqrt{2} \ \Omega$
D.$5\sqrt{2} \ \Omega$
MediumSolve

Why 32,000+ students choose TopperSquare

Everything you need to crack NEET

15,000+ Chapter MCQs

Physics, Chemistry, Biology — chapter-wise, topic-wise practice

AI Performance Analytics

Know your weak topics. Get a personalised study plan.

Full NEET Mock Tests

180 questions, timed, with detailed score analysis

PYQ Sets 2010–2024

15 years of past papers with solved explanations

Start Practising Free

No credit card · 30-second signup · Free forever plan included

This neet physics practice question is part of the TopperSquare free question bank. TopperSquare offers 15,000+ chapter-wise NEET MCQs across Physics, Chemistry, and Biology with detailed step-by-step explanations, full mock tests, NEET PYQs (2010–2024), and an AI-powered performance analytics dashboard. browse all neet practice questions → · practice physics sets →

Explore more subjects:Physics MCQs•Chemistry MCQs•Biology MCQs•Botany MCQs•Zoology MCQs•NEET Mock Tests•NEET PYQs