Murphy built a simple motor with a battery, permanent magnet, copper coil of wire and iron bar. when the motor is turned on, the iron bar and coil spin in a circle to produce electricity, explain the energy transformations occurring in the motor

Energy transformation between mechanical energy and electrical energy

Explanation:

Generally, when the copper coil and the iron bar rotate in a circular direction, there is change in the magnetic flux, and as a result an electromotive force (also known as EMF) is generated. The induced electromotive force is the voltage produced due to the presence of magnetic force due to the rotation of the coil and iron bar. Thus, the energy transformation between mechanical energy and electrical energy occurs.

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a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.