Answer:
ν = 5.45 x 10¹⁴ Hz
Explanation:
given,
wavelength of light = 550 nm
= 550 x 10⁻⁹ m
speed of light = 1.96 x 10⁸ m/s
speed of sound = 3 x 10⁸ m/s
frequency of the light = ?
we know.

frequency of the light in the liquid is same as the frequency of the light in the air.
ν is the frequency of light


ν = 5.45 x 10¹⁴ Hz
Hence, the frequency of light in the liquid is equal to ν = 5.45 x 10¹⁴ Hz
Explanation:
the speed of the motor can be increased by increasing the strength magnetic field increasing the current flowing through the coil.