## Michelson’s Interferometer

Varhsa asks:

“What is Michelson Interferometer?”

Please refer to the following links for a detailed answer.

## What energises the secondary of the Transformer?

Jamie asks:

“I am told that no magnetism escapes from a transformer due to the closed loop. If that is the case, what is energizing the secondary winding?”

## A Problem based on Bernoulli’s Equation

Hannah asks:

“Water moves through a constricted pipe in steady, ideal flow. At the lower point , the pressure is 1.75×10^5 Pa and the pipe radius is 3.00 cm. At another point, 2.50 m higher, the pressure is 1.20X10^5 Pa and the pipe radius is 1.50 cm.Find the speed of flow in a)the upper section, b)the lower section, c) find the volume flow rate through the pipe.”

## A Problem from Diffraction Grating.

Viviana asks:

“Light of wavelength 450 nm is incident normally on a grating with 300 lines per millimeter. How many orders of diffraction maxima can be obtained?”

## A problem from current electricity

Sakshi posted:

“the resistance of a coil of a small motor of 10 watts,20 volts is 12 ohm.what is the rate of heat produced in the motor”

## why sound travel faster in moist air than in dry air?

Raza Asks:

“Why sound travel faster in moist air than in dry

air?”

Answer:

The density of dry air is more than that of moist air (Wonder why? Just answer me – which is denser – skimmed milk or fresh milk. The cream is lighter and when removed from milk, we get skimmed milk and therefore skimmed milk will be denser than the fresh one with cream content. Just like that the water vapor is lighter than dry air. When moisture is removed from air, its density increases). The speed of sound in a medium is inversely proportional to the square root of its density. Therefore, the speed of sound in moist air is more than that in dry air.

## Numerical Problem from Capacitance

Nishant asks:

“In the diagram, what is the potential difference between A and B? Please explain the procedure.”

(Due to the large number of questions I am receiving per day, I am posting the question first and I will answer them later. Visitors, please feel free to respond to the answered and unanswered questions.)