A 100 W resistor is connected to a 220 V, 50 Hz ac supply.
(a) What is the rms value of current in the circuit?
(b) What is the net power consumed over a full cycle?
A 100 W resistor is connected to a 220 V, 50 Hz ac supply.
(a) What is the rms value of current in the circuit?
(b) What is the net power consumed over a full cycle?
Solution and Explanation
Resistance of the resistor, R = 100 Ω
Supply voltage, V = 220 V
Frequency, ν = 50 Hz
(a) The rms value of current in the circuit is given as
\(I=\frac{V}{R} = \frac{220}{100} = 2.20A\)
(b) The net power consumed over a full cycle is given as:
P = VI = 220 × 2.2 = 484 W
Top Questions on Alternating Current
- An ac source of voltage \( v = v_m \sin \omega t \) is connected to a series combination of LCR circuit. Draw the phasor diagram. Using it, obtain an expression for the impedance of the circuit and the phase difference between applied voltage and the current.
- CBSE CLASS XII - 2025
- Physics
- Alternating Current
- A voltage \( v = v_0 \sin \omega t \) applied to a circuit drives a current \( i = i_0 \sin (\omega t + \phi) \) in the circuit. The average power consumed in the circuit over a cycle is:
- CBSE CLASS XII - 2025
- Physics
- Alternating Current
- Differentiate between the peak value and root mean square value of an alternating current. Derive the expression for the root mean square value of alternating current, in terms of its peak value.
- CBSE CLASS XII - 2025
- Physics
- Alternating Current
The alternating current \( I \) in an inductor is observed to vary with time \( t \) as shown in the graph for a cycle.
Which one of the following graphs is the correct representation of wave form of voltage \( V \) with time \( t \)?}
- CBSE CLASS XII - 2025
- Physics
- Alternating Current
- An AC power supply of 220 V at 50 Hz, a resistor of 20\( \Omega \), a capacitor of reactance 25\( \Omega \) and an inductor of reactance 45\( \Omega \) are connected in series. The corresponding current in the circuit and the phase angle between the current and the voltage is, respectively :
- NEET (UG) - 2025
- Physics
- Alternating Current
Questions Asked in CBSE CLASS XII exam
- Find the least value of ‘a’ so that $f(x) = 2x^2 - ax + 3$ is an increasing function on $[2, 4]$.
- CBSE CLASS XII - 2025
- Functions
- Transplantation of tissues/organs to some patients often fails due to rejection by the body of the patient. Which type of immune response is responsible for such rejections?
- CBSE CLASS XII - 2025
- Human health and disease
- You are Kirti / Keshav of 7, M.G. Road, Jhansi. You are disturbed by students littering parks during one-day picnics. Write a letter to the editor of a national daily suggesting ways to inculcate civic sense among students. Use the given cues to draft the letter.
- CBSE CLASS XII - 2025
- Writing Skills
- Assertion (A): Molecularity of reaction is determined experimentally. Reason (R): Molecularity is applicable only for an elementary reaction and not for a complex reaction.
- CBSE CLASS XII - 2025
- Chemical Kinetics
- The integrating factor of the differential equation \( \frac{dy}{dx} + y = \frac{1 + y}{x} \) is:
- CBSE CLASS XII - 2025
- Integration
Concepts Used:
AC Voltage
When voltage changes its direction after every half cycle is known as alternating voltage. The current flows in the circuit at that time are known as alternating current. The alternating current(AC) follows the sine function which changes its polarity concerning time. Most of the electrical devices are operating on the ac voltage.
