Arrange the following in the ascending order of wavelength ( $\lambda$ ) : (A) Microwaves $\left(\lambda_{1}\right)$ (B) Ultraviolet rays ( $\lambda_{2}$ ) (C) Infrared rays ( $\lambda_{3}$ ) (D) X-rays $\left(\lambda_{4}\right)$ Choose the most appropriate answer from the options given below :-

(C) $\lambda_{4}<\lambda_{2}<\lambda_{3}<\lambda_{1}$

(A) $\lambda_{4}<\lambda_{3}<\lambda_{2}<\lambda_{1}$

(B) $\lambda_{3}<\lambda_{4}<\lambda_{2}<\lambda_{1}$

(D) $\lambda_{4}<\lambda_{3}<\lambda_{1}<\lambda_{2}$

JEE Main · 2025 · 24 Jan 2025 · Shift 2 · EM Waves

Arrange the following in the ascending order of wavelength (

λ

) :
(A) Microwaves

(λ_{1})

(B) Ultraviolet rays (

λ_{2}

)
(C) Infrared rays (

λ_{3}

)
(D) X-rays

(λ_{4})

Choose the most appropriate answer from the options given below :-

Answer: (C)

The electromagnetic spectrum in order of increasing wavelength (decreasing frequency and photon energy) runs

γ -rays < X-rays < UV < visible < IR < microwaves < radio waves .

Matching to the given labels: X-rays

(λ_{4})

have the shortest wavelength among the four, followed by ultraviolet

(λ_{2})

, then infrared

(λ_{3})

, and microwaves

(λ_{1})

have the longest. The ascending order is

λ_{4} < λ_{2} < λ_{3} < λ_{1} .

JEE Main · 2025 · 24 Jan 2025 · Shift 2 · Single correct option