Alternating Current Important Questions for NEET 2025 PDF

Alternating Current Important Questions for NEET: Alternating Current (AC) is an essential topic in physics that you must understand for the NEET exam . It involves the flow of electric charge that changes direction periodically. In this article, we will cover the basics of AC, and its importance in the NEET 2025 exam, and provide some sample practice questions to help you prepare. Additionally, we’ll mention some helpful resources for your NEET preparation.

Alternating Current Important Questions for NEET Overview

Alternating current (AC) is an important concept in Physics, especially for competitive exams like NEET.This article gives the key ideas about alternating current, some practice questions, and resources to help you prepare for your NEET exam.

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What is Alternating Current?

Alternating Current (AC) is a type of electrical current that changes direction periodically. Unlike Direct Current (DC), where the flow of electricity is in one direction, AC changes direction back and forth. This is the type of current that powers most of our household appliances and is commonly used for electricity transmission over long distances.

In an AC circuit, the current follows a sinusoidal waveform, meaning it rises and falls smoothly in a pattern. The number of cycles the current completes per second is called the frequency, measured in hertz (Hz). In India, the standard frequency for AC is 50 Hz, meaning the current changes direction 50 times per second.

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Practice Questions for Alternating Current for NEET

Here, we provide some sample questions on alternating current to help you practice. You can use these questions to test your understanding of the topic.

Q1. For an alternating current varying with time according to the relation I=I0sin⁡ωtI identify the correct relation between I0,IrmsI_0, is the peak value, Irms is the root mean square value and Iav ​ is the average value):

1. I0=Irms=Iav ​
2. I0>Irms>Iav ​
3. I0<Irms=Iav ​
4. I0<Irms<Iav ​

Q2. If alternating current in a circuit is given by:

I=I0sin⁡2πnt , then the minimum time taken by the current to change from rms value to zero is equal to:

1. 1n\frac{1}{n} n 1 ​
2. 12n\frac{1}{2n} 2 n 1 ​
3. 14n\frac{1}{4n} 4 n 1 ​
4. 18n\frac{1}{8n} 8 n 1 ​

Q3. The peak value of an alternating e.m.f. E=E0sin⁡ωtE = E_0 \sin \omega t E = E 0 ​ sin ω t is 10 volt and its frequency is 50 Hz. At a time t=1600 st = \frac{1}{600} , the instantaneous value of the e.m.f. is:

1. 1 volt
2. 53 volt5 \sqrt{3}
3. 5 volt
4. 10 volt

Q4. An alternating voltage is represented as $E=20\sin 300t$ . The average value of voltage over one cycle will be:

1. Zero
2. 10 volt
3. 20 2 volt\sqrt{2}
4. 202 volt\frac{20}{\sqrt{2}}

Q5. In a purely resistive a.c. circuit, the current:

1. Lags behind the e.m.f. in phase
2. Is in phase with the e.m.f.
3. Leads the e.m.f. in phase
4. Leads the e.m.f. in half the cycle and lags behind it in the other half

Q6. The inductive reactance of an inductor of 1π henry at 50 Hz frequency is:

1. 50π ohm
2. π50 ohm
3. 100 ohm
4. 50 ohm

Q7. Statement-I: The r.m.s. value of alternating current is defined as the square root of the average of I2I^2 I 2 during a complete cycle. Statement-II: For sinusoidal a.c. ( I=I0sin⁡ωt) Irms=I0\sqrt2 ​ ​ .

1. Statement I and Statement II both are correct.
2. Statement I is correct but Statement II is incorrect.
3. Statement I is incorrect but Statement II is correct.
4. Statement I and Statement II both are incorrect.

Q8. An alternating voltage E (in volts)=2002sin⁡100t is connected to one micro farad capacitor through an a.c. ammeter. The reading of the ammeter shall be:

1. 100 mA
2. 20 mA
3. 40 mA
4. 80 mA

Alternating Current Important Questions for NEET PDF

PhysicsWallah is providing a PDF for the Alternating Current Important Questions for NEET chapter under the Prachand NEET Batch 2025 . This PDF contains important questions and their answers, along with detailed explanations to help students better understand the concepts. You can download this PDF for free to aid in your NEET preparation.

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