When electrons in the transmitting antenna vibrate 94000 times per second, they produce radiowaves having frequency:
Correct answer: C. 94 kHz
- A. 9.4 kHz
- B. 940 kHz
- C. 94 kHz
- D. None of these
Explanation
This is the correct answer. When electrons in the transmitting antenna vibrate at a frequency of 94,000 times per second, the resulting radio waves have a frequency of 94 kHz. The unit "kHz" stands for kilohertz, which represents a frequency of 1,000 cycles per second. Therefore, 94 kHz corresponds to 94000 cycles per second, which is close to the given vibration frequency. f=94000 Cs-1f=94 x 103 Hz = 94 kHz
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: