Question

Which one of the following correctly represents the change in wave characteristics (all in vacuum) from microwaves to X-rays in electromagnetic spectrum?

• A. Speed remains same, Wavelength decreases, Frequency remains same
• B. Speed remains same, Wavelength decreases, Frequency increases
• C. Speed increases, Wavelength increases, Frequency decreases
• D. Speed remains same, Wavelength increases, Frequency remains same

Hint:

In the electromagnetic spectrum, the speed of light is constant in a vacuum, but the wavelength and frequency are inversely related. As wavelength decreases, frequency increases.

Answer 1

The Correct Option is B

To understand the change in wave characteristics from microwaves to X-rays in the electromagnetic spectrum, we need to consider the general properties of electromagnetic waves: 

• Speed: Electromagnetic waves travel at the same speed in a vacuum, which is approximately c = 3 × 10⁸ m/s. Therefore, the speed remains constant across the spectrum.
• Wavelength and Frequency: The relationship between speed (c), frequency (f), and wavelength (λ) is given by the equation c = λf. When the speed is constant, any change in wavelength results in an inverse change in frequency.

From microwaves to X-rays:

• Wavelength: Generally decreases. Microwaves have longer wavelengths compared to X-rays.
• Frequency: Increases. Since their wavelengths decrease, their frequencies must increase to maintain the constant speed, according to the formula.

Thus, the correct change in wave characteristics from microwaves to X-rays is: "Speed remains same, Wavelength decreases, Frequency increases." This is captured in the correct answer given.