NEET Physics Alternating Current Class 12 Questions

A light bulb and an open coil induction are connected in series to an ac source as shown in figure. Now an iron rod is inserted into the interior of the inductor. The glow of the light bulb

A 50 Hz a.c. source of 20 volts is connected across R and C as shown in figure. The voltage across R is 12 volts. The voltage across C is:

An ac circuit contains a resistance of 1 kΩ, a capacitor of 0.1 μF and an inductor of 1 mH connected in series. The resonance frequency of the circuit is approximately:

The peak value of an alternating current is 5 Å and frequency is 60 Hz. How long will the current, starting from zero, take to reach the peak value?

AB is a part of an electrical circuit (see figure). The potential difference "Vₐ - V_b", at the instant when current i = 2 Å and is increasing at a rate of 1 amp / second is:

To an ac power supply of 220 V at 50 Hz, a resistor of 20 Ω, a capacitor of reactance 25 Ω and an inductor of reactance 45 Ω are connected in series. The corresponding current in the circuit and the phase angle between the current and the voltage is, respectively -

A 10 μF capacitor is connected to a 210 V, 50 Hz source as shown in figure. The peak current in the circuit is nearly (π = 3.14):

In a series LCR circuit, the inductance L is 10 mH, capacitance C is 1 μF and resistance R is 100 Ω. The frequency at which resonance occurs is :

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

The peak voltage of the ac source is equal to:

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 v₀ and the frequency of the ac source is v, then:

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 as shown in figure. Potential difference across L, C and R is 40 V, 10 V and 40 V, respectively. The amplitude of current flowing through LCR series circuit is 10√2 Å. The impedance of the circuit is :

A series LCR circuit containing 5.0 H inductor, 80 μF capacitor and 40 Ω resistor is connected to 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 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 is connected to an ac voltage source. When L is removed from the circuit, the phase difference between current and voltage is π/3. If instead C is removed from the circuit, the phase difference is again π/3 between current and voltage. The power factor of the circuit is:

A resistance wire connected in the left gap of a metre bridge balances a 10 Ω resistance in the right gap at a point which divides the bridge wire in the ratio 3 : 2. If the length of the resistance wire is 1.5 m, then the length of 1 Ω of the resistance wire is:

An inductor 20 mH, a capacitor 100 μF and a resistor 50 Ω are connected in series across a source of emf, \( V = 10 \sin 314\, t \). The power loss in the circuit is

An inductor 20 mH, a capacitor 50 μF and a resistor 40 Ω are connected in series across a source of emf V = 10 sin340t. The power loss in A.C. circuit is

A small signal voltage V(t) = V₀ sinωt is applied across an ideal capacitor C

A resistance R draws power P when connected to an AC source. If an inductance is now placed in series with the resistance, such that the impedance of the circuit becomes Z, the power drawn will be