List of top Physics Questions on Alternating current

In an ideal step up transformer, the number of turns in primary coil and secondary coil are 100 and 200 respectively. If output current is found to be 5A, then input current will be ______.
A charged 30 $\mu$F capacitor is connected to a 27 mH inductor. What is the angular frequency of free oscillations of the circuit?
A 15.0 $\mu$F capacitor is connected to a 220 V, 50 Hz source. Then capacitive reactance of the circuit is ______ $\Omega$.
Two blocks with masses 100 g and 200 g are attached to the ends of springs A and B as shown in figure. The energy stored in A is E. The energy stored in B, when spring constants \(k_A, k_B\) of A and B, respectively satisfy the relation \(4k_A = 3k_B\), is :
For the series LCR circuit connected with $220\,\text{V},\,50\,\text{Hz}$ a.c. source as shown in the figure, the power factor is $\dfrac{\alpha}{10}$. The value of $\alpha$ is ___.
Electric current in a circuit is given by \(i = i_0 \frac{t}{T}\), then find the rms current for period t = 0 to t = T :

Find capacitance $C$ for the given circuit.
Given: \( L = 20\text{ H}, \quad R = 100\Omega, \quad \omega = 100\text{ rad/s} \)
The applied voltage and current are: \[ V = V_0 \sin \omega t, \quad i = i_0 \sin \omega t \]

The rms and the average value of an AC voltage \( V = V_0 \sin \omega t \) over a cycle respectively will be:

The electric potential (V ) and electric field (⃗ E) are closely related concepts in electrostatics. The electric field is a vector quantity that represents the

Explain the principle and working of an AC Generator or a Transformer (including energy losses).
The electric current in the circuit is given as \[ i=i_0\left(\frac{t}{T}\right). \] The r.m.s. current for the period \( t=0 \) to \( t=T \) is:
Does a step up transformer contradict the principle of conservation of energy? Justify your answer.
Can a step up transformer work as a step down transformer?
Can a transformer step up or step down dc power supply?
Differentiate between inductive reactance, capacitive reactance and impedance of an ac circuit.
An ideal inductor and an ideal capacitor are connected in series across an ac voltage. Plot a graph showing variation of net reactance of the circuit with frequency of the applied ac voltage.
Which of the following statements is not true for electric energy in ac form compared to that in dc form?
The rms and the average value of an ac voltage \(V = V_0 \sin \omega t\) volt over a cycle respectively will be:
Find the energy density at the instant when the current is \( \dfrac{1}{e} \) times its maximum value. If the value obtained is \( \alpha \dfrac{\pi}{e^2} \), find \( \alpha \). Given: \[ \varepsilon = 10\,\text{V}, \quad R = 10\,\Omega, \quad L = 10\,\text{mH}, \quad \frac{N}{\ell} = 10000 \]
Figure shows a circuit consisting capacitor, inductor and a resistor connected in series with an AC source. Find the power factor of the circuit.
(Given R = 60$\Omega$, X\(_{L}\) = 150$\Omega$, X\(_{C}\) = 70$\Omega$)
In the given L-C circuit, charge on the capacitor is maximum at \( t = 0 \), find the time at which charge becomes 25% of its initial value for the first time.
In an LCR series circuit, if $\frac{1}{\omega C}<\omega L$, then the incorrect option among the following is ($\omega$-angular frequency, C-capacitance and L-inductance)
The small energy losses in transformers due to eddy currents can be reduced by
A capacitor and a resistor of resistance $100\sqrt{3}\Omega$ are connected in series to an ac source of voltage $100\sin(200t)$ V, where 't' is time in second. If the phase difference between the voltage and the current in the circuit is 30$^\circ$, then the capacitance of the capacitor is
An electric bulb, an open coil inductor, an ac source and a key are all connected in series to form a closed circuit. The key is closed and after some time an iron rod is inserted into the interior of the inductor, then
An alternating current is given by \( I = I_0 \cos (100\pi t) \). The least time the current takes to decrease from its maximum value to zero will be: