What is the instantaneous power dissipated through a resistor of resistance 10 ohm if it is connected to an AC source of frequency 15 Hz at 1/180 sec if peak value is 20 V?
Correct answer: A. 10 W
- A. 10 W
- B. 100 W
- C. 40 W
- D. Cannot be determined
Explanation
UsingVo = V sin(2𝜋ft) = 20 x sin (2𝜋 x 15 x 1/180) = 10 VUsingP = v2/ R = 102 / 10 = 10 W
Last updated
About Alternating Current
Alternating current varies periodically, so phase relationships become essential when current passes through a resistor, capacitor or inductor. The chapter distinguishes resistance from capacitive and inductive reactance, explains phase lead and lag, and connects changing electric and magnetic fields with the production and properties of electromagnetic waves.
Practise Alternating Current
592 free Alternating Current MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
220V, 50 Hz AC supply is connected across a resistor of 50 k ohms. The current at time t Seconds, assuming that it is zero at t = O, is?
220V, 50 Hz AC supply is connected across a resistor of 50 k ohms. The current at time t Seconds, assuming that it is zero at t = O, is?
A 10 Ω resistor and a 40 μF capacitor are connected in parallel to a 110 V, 50 Hz AC supply. The total current is:
A 100 μF capacitor is connected to a 120 V (rms) AC source at 50 Hz. What is the rms current in the circuit?
A 100 μf capacitor will offer a reactance of: