JEE Main 16 March 2021 Shift 2 Solved Paper

Since, λv=c= constant
where, λ= wavelength of light
and v= frequency of light.
Red light and blue light have different wavelengths and different frequencies but same speed.
⇒‌‌R=‌

H

I2T

.....(i)
Substituting the given values in Eq. (i), we get
R=‌

10×10−3

(2×10−3)2×1

⇒‌‌R=‌

10−2

4×10−6

⇒R=0.25×104
⇒‌‌R=2500Ω