Draw a ray diagram to show the refraction of a monochromatic ray through a prism when it suffers minimum deviation.
The human ear can detect continuous sounds in the frequency range from 20 Hz to 20,000 Hz. Assuming that the speed of sound in air is 330 ms-1 for all frequencies; calculate the wavelengths corresponding to the given extreme frequencies of the audible range.
Applying the formula, v = λ x ν
where, v = velocity of sound =330 ms-1
ν = frequency
λ = wavelength of sound
We have a range of frequencies from 20 Hz−20,000 Hz.
Hence, for frequency ν = 20 Hz, we have
330 = 20 ×λ
⇒λ = 330/20 = 16.5 m
For frequency ν = 20,000 , Hz, we have
330= 20000 ×λ
⇒ λ = 330/20000 = × 16.5 x10-3 m
An enemy plane is at a distance of 300 km from a radar. In how much time the radar will be able to detect the plane? Take velocity of radio waves as x 108 ms-1.
How is the frequency of a stretched string related to:
(i) it’s length
(ii) it’s tension?
An electric bulb of 300 Ω draws a current of 0.4 A. Calculate the power of the bulb and the potential difference at its ends.