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
- 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
- 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
- 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
- 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
- A resistor and an ideal inductor are connected in series to a \( 100 \sqrt{2} \, \text{V}, 50 \, \text{Hz} \) AC source. When a voltmeter is connected across the resistor or the inductor, it shows the same reading. The reading of the voltmeter is:
- CBSE CLASS XII - 2024
- Physics
- Alternating Current
Questions Asked in CBSE CLASS XII exam
A certain reaction is 50 complete in 20 minutes at 300 K and the same reaction is 50 complete in 5 minutes at 350 K. Calculate the activation energy if it is a first order reaction. Given: \[ R = 8.314 \, \text{J K}^{-1} \, \text{mol}^{-1}, \quad \log 4 = 0.602 \]
- CBSE CLASS XII - 2025
- Organic Reactions
- Using integration, find the area of the region bounded by the line \[ y = 5x + 2, \] the \( x \)-axis, and the ordinates \( x = -2 \) and \( x = 2 \).
- CBSE CLASS XII - 2025
- Evaluation of Definite Integrals by Substitution
- In case the total cost of a machine less installation charges is greater than Rs 2,00,000, then 20% depreciation is charged, and if total cost of the machine is less than Rs 2,00,000 then 10% depreciation is charged.
Write the steps to create the 'IF' function using the Formula tab and dialogue box on a given spreadsheet. Also, write the syntax of the result.- CBSE CLASS XII - 2025
- Computerised Accounting
- Name the error which occurs when Excel doesn't recognize a Text formula. Give any two solutions to correct it.
- CBSE CLASS XII - 2025
- Basic Knowledge of Excel
- Null value is the special value which represents :
- CBSE CLASS XII - 2025
- Computerised Accounting
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.
