Question

The frequency order for X-rays(A), γ rays(B), UV rays(C) is
(A) $B > A> C$
(B) $A > B >C$
(C) $C > B >A$
(D) $A > C >B$

Answer 1

Hint
Frequency is the number of occurrences of a repeating event per unit of time. It is also referred to as temporal frequency, which emphasizes the contrast to spatial frequency and angular frequency. Frequency is measured in units of hertz which is equal to one occurrence of a repeating event per second.

Complete step by step answer
X-rays are high-frequency, and thus high-energy, electromagnetic radiation. They have wavelengths ranging from $0.01$ to $10$ nanometres, and thus frequencies from $3 \times {10}^{19}$ to $3 \times {10}^{16}$ Hz.Gamma-rays have frequencies greater than about $10^{19}$ cycles per second, or hertz (Hz), and wavelengths of less than 100 picometers (pm), or $4 \times 10^9$ inches. (A picometer is one-trillionth of a meter.)Ultraviolet (UV) light falls in the range of the EM spectrum between visible light and X-rays. It has frequencies of about $8 \times 10^{14}$ to $3 \times 10^{16}$ cycles per second, or hertz (Hz), and wavelengths of about $380 \,nanometers (1.5 \times 10^{−5} inches) $ to about $10 nm$ ($4 \times 10^{−7} inches$).
So, we can say, according to the value that, In the electromagnetic spectrum, the wavelength order of these waves is: $C > A > B$.
So the order of frequencies will be $B > A > C$, Option (A) is correct.

Note
Frequency measures the number of times something occurs in a specific amount of time. While frequency can be used to measure the rate of any action, in technical applications it is typically used to measure wave rates or processing speed.