List of top Physics Questions on Alternating current asked in NEET (UG)

In a series LCR circuit, the inductance L is 10 mH, Capacitance C is 1μF and resistance R is 100Ω. The frequency at which resonance occurs is
An ac source is connected to a capacitor C. Due to decrease in its operating frequency:
A 12V, 60W lamp is connected to the secondary of a step down transformer, whose primary is connected to ac mains of 220V. Assuming the transformer to be ideal, what is the current in the primary winding?
A series LCR circuit with inductance 10 H, capacitance 10 μF, resistance 50 Ω is connected to an ac source of voltage, V =200 sin(100 t) volt. If the resonant frequency of the LCR circuit is vo and the frequency of the ac source is v, then:
The peak voltage of the ac source is equal to:
A long solenoid of radius 1 mm has 100 turns per mm. If 1 A current flows in the solenoid, the magnetic field strength at the centre of the solenoid is:

A step-down transformer connected to an ac mains supply of 220 V is made to operate at 11 V, 44 W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit

A series LCR circuit containing a 5.0 H inductor, 80 µF capacitor and 40 Ω resistor is connected to a 230 V variable frequency ac source. The angular frequencies of the source at which power transferred to the circuit is half the power at the resonant angular frequency are likely to be
A $40\, \mu\,F$ capacitor is connected to a $200\,V$,$50\,Hz$ ac supply. The rms value of the current in the circuit is, nearly :
A series LCR circuit is connected to an ac voltage source. When L is removed from the circuit, the phase difference between current and voltage is $\frac {\pi}{3}$ . If instead C is removed from the circuit, the phase difference is again $\frac {\pi}{3}$ between current and voltage. The power factor of the circuit is :
A circuit when connected to an $AC$ source of $12\, V$ gives a current of $0.2\, A$. The same circuit when connected to a $DC$ source of $12\, V$, gives a current of $0.4 \,A$. The circuit is
An inductor $20\, mH$, a capacitor $50\, \mu F$ and a resistor $40 \, \Omega $ are connected in series across a source of emf $V = 10 \, \sin \, 340\,t$. The power loss in A.C. circuit is :
Which of the following combinations should be selected for better tuning of an $L-C-R$ circuit used for communication ?
A direct current of $5\, A$ is superposed on an alternating current $I = 10 \,\sin \omega t$ flowing through the wire. The effective value of the resulting current will be
A transformer having efficiency of 90% is working on $200\, V$ and $3 \,kW$ power supply. If the current in the secondary coil is $6\, A$, the voltage across the secondary coil and the current in the primary coil respectively are
A coil is self-inductance $L$ is connected in series with a bulb $B$ and an $AC$ source. Brightness of the bulb decreases when :
A coil has resistance $30$ ohm and inductive reactance $20$ ohm at $50 \,Hz$ frequency. If an ac source, of $200$ volt, $100\, Hz$, is connected across the coil, the current in the coil will be

An ac voltage is applied to a resistance R and an inductor L in series. If R and the inductive reactance are both equal to 3Ω, the phase difference between the applied voltage and the current in the circuit is

A $220\, volt$ input is supplied to a transformer. The output circuit draws a current of $2.0$ ampere at $440\, volts$. If the efficiency of the transformer is $80\%$, the current drawn by the primary windings of the transformer is
A condenser of capacity $C$ is charged to a potential difference of $V_1$. The plates of the condenser are then connected to an ideal inductor of inductance $L$. The current through the inductor when the potential difference across the condenser reduces to $V_2$ is

In the given circuit the reading of voltmeter \(V_1\) and \(V_2\) are \(300\) volts each. The reading of the voltmeter \(V_3\) and ammeter \(A\) are respectively

For a coil having L = 2 mH, current flow through it is $I= t^2e^{-l}$ then, the time at which emf become zero
In an A.C. circuit, the current flowing is \(I=5sin(100 t - \frac{π}{2}) ampere\) and the potential difference is \(V = 200 sin (100 t) volts\). The power consumption is equal to