We simply asked to name three uses for mercury.
The most common and well-known use of mercury is the production of thermometers. It's property to stay liquid at room temperature makes it ideal for a temperature indicator. However, the use of mercury is thermometers has been phased out due to health hazards.
It is also used to form an amalgam which is the result of its combination with silver or gold. Mercury has been used to mine gold and silver. This application has also been phased out.
Today's use of mercury includes mercury-vapor lamps which are the bright lamps used in high-ways.
Answer:
(A). The order of the bright fringe is 6.
(B). The width of the bright fringe is 3.33 μm.
Explanation:
Given that,
Fringe width d = 0.5 mm
Wavelength = 589 nm
Distance of screen and slit D = 1.5 m
Distance of bright fringe y = 1 cm
(A) We need to calculate the order of the bright fringe
Using formula of wavelength


Put the value into the formula


(B). We need to calculate the width of the bright fringe
Using formula of width of fringe

Put the value in to the formula



Hence, (A). The order of the bright fringe is 6.
(B). The width of the bright fringe is 3.33 μm.
The feather's vertical position
is determined by

We take the feather's starting position to be the origin, and the downward direction to be positive. Then

so the answer is D.