Answer:
4.4 cm
Explanation:
Given:
Distance of the screen from the slit, D = 1 m
Distance between two third order interference minimas, x = 22 cm
Let's say, minima occurs at:

We have:

Calculating further for the width of the central bright fringe, we have:

= 4.4 cm
Note: w in representswavelength
Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is derived from the Latin globulus—a small sphere.
The highest point of a wave is called the crest. Among the choices, the correct answer is C. The height of the wave can be determined using the crest and the trough. The trough is the lowest point of a wave. The wavelength is the distance between two crests of a wave.
Solution :
Frequency may be defined as the number of observation or number of waves that is taken in per unit time. The unit of frequency is Hertz or Hz.
It is given that :
Successive harmonic frequencies, f = 52.2 Hz
and f' = 60.9 Hz
Therefore, fundamental frequency, F = f' - f
F = 60.9 - 52.2
F = 8.7 Hz
Therefore the string which is fixed at both the ends forms all the harmonics.