Advertisements
Advertisements
Question
A beam of light travels from air into a medium. Its speed and wavelength in the medium are 1.5 × 108 ms-1 and 230 nm respectively. The wavelength of light in the air will be ______.
Options
230 nm
345 nm
460 nm
690 nm
Solution
A beam of light travels from air into a medium. Its speed and wavelength in the medium are 1.5 × 108 ms-1 and 230 nm respectively. The wavelength of light in the air will be 460 nm.
Explanation:
We know that,
Speed = Wavelength × Wave frequency
In this equation, the wavelength is measured in meters, and frequency is measured in hertz (Hz), or the number of waves per second.
Given: v2 (speed of medium) = `1.5 xx 10^8`, Wavelength (λ2) = 230 nm, speed of light in air (v1) = `3 xx 10^8` m/s
To find: Wavelength of air(λ1)
∴ `v_1/lambda_1 = v_2/lambda_2`
`3 xx 10^8 xx 230 = 1.5 xx 10^8 xx lambda_1`
`lambda_1 = 460` nm
APPEARS IN
RELATED QUESTIONS
A diver under water, looks obliquely at a fisherman standing on the bank of a lake. Would the fisherman look taller or shorter to the diver than what he actually is?
A point object is placed at a distance of 30 cm from a convex mirror of focal length 30 cm. The image will form at
A narrow beam of white light goes through a slab having parallel faces.
(a) The light never splits in different colours
(b) The emergent beam is white
(c) The light inside the slab is split into different colours
(d) The light inside the slab is white
A pole of length 1.00 m stands half dipped in a swimming pool with water level 50.0 cm higher than the bed. The refractive index of water is 1.33 and sunlight is coming at an angle of 45° with the vertical. Find the length of the shadow of the pole on the bed.
What is relative refractive index?
Write a short note on the prisms making use of total internal reflection.
Derive the equation for acceptance angle and numerical aperture, of optical fiber.
For a rectangular slab, refraction takes place at ______.
A ray of unpolarised light is incident on the surface of glass plate of µ = 1.54 at polarising angle, then angle of refraction is
