Which one of the following properties of electromagnetic waves does not change in a vacuum?
Correct answer: A. Speed
- A. Speed
- B. Wavelength
- C. Frequency
- D. All of the above
Explanation
Electromagnetic waves travel at a constant speed of approximately 3 × 10^8 m/s in a vacuum. This speed is a fundamental property of the medium (the vacuum itself) and does not change with the frequency or wavelength of the wave. Wavelength and frequency are related through the equation c = fλ, where c is the speed of light, f is the frequency, and λ is the wavelength. In a vacuum, as the frequency changes, the wavelength adjusts to maintain the constant speed of light. Therefore, the speed of electromagnetic waves is the property that does not change in a vacuum.
Last updated
About Electromagnetic Waves
Electromagnetic waves consist of mutually perpendicular, oscillating electric and magnetic fields that also remain perpendicular to the direction of propagation. They travel through vacuum at the speed of light and include radio waves, microwaves, infrared, visible, ultraviolet, X-rays and gamma rays. Unlike mechanical waves, they do not require a material medium.
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
1) A choke is used for resistance in _
A 10-ohm electric heater is connected to a 220V, 50Hz main supply. What is the peak value of the potential differences across the heater element:
A changing magnetic flux produces around itself as induced:
a voltmeter has resistance of 2000 ohms and it can measure up to 2V. if we want to increase its range to 10V then required resistance in series will be
Accelerating electromagnetic charges radiate electromagnetic waves which propagate at the