NEET Eligibility Criteria 2025 By NTA - Age Limit, Number of Attempt, Education Qualification

AC Voltage Applied To A Resistor MCQ - Practice Questions with Answers

Edited By admin | Updated on Sep 25, 2023 25:23 PM | #NEET

Quick Facts

AC voltage applied to a resistor is considered one of the most asked concept.
7 Questions around this concept.

Solve by difficulty

MEDIUM

A $50\Omega$ electric heater is connected to 100 V, 60 Hz are supply.

The peak value of the Voltage is 100 V

The peak value of the current in the circuit is $2 \sqrt{2} \mathrm{~A}$

The rms value of the voltage is 100 V

The rms value of the current is 2A

View Solution

If the phase difference between voltage and current is $\frac{\pi }{6}$ and the resistance in the circuit is $\sqrt{300}\Omega$ , then the impedance of the circuit will be

$\mathrm{40 \Omega}$

$\mathrm{20 \Omega}$

$\mathrm{50 \Omega}$

$\mathrm{13 \Omega}$

View Solution

Concepts Covered - 1

AC voltage applied to a resistor

AC voltage applied to a resistor:

When a constant voltage source or battery is applied across a resistor current is developed in resister. This current has a unique direction and flows from the negative terminal of a battery to positive terminal. The magnitude of the current remains constant as well. If Direction of current through resistor changes periodically then current is called alternating current.

Voltage V(t) is applied across resistance R. V(t) is sinusoidal voltage with peak V_m and time period T.

$T=\frac{1}{f}=\frac{2 \pi}{\omega}$

Where f is frequency and ω is angular frequency . This kind of circuit is a purely resistive circuit. According to Kirchhoff’s law –

$\begin{aligned} v(t) &=R i(t) \\ i(t) &=\frac{v(t)}{R} \\ i(t) &=\frac{V_{m} \sin (\omega t)}{R} \\ i_{m} &=\frac{V_{m}}{R} \\ i(t) &=i_{m} \sin (\omega t) \end{aligned}$