Answer:
In a primary cell, two electrodes (one of copper and other of zinc) of metal atoms are used. These electrodes are dipped in an electrolyte solution that causes the metals to produce their respective positive and negative ions.
In this way, the flow of charges takes place and supply the electricity to the source.
Unlike a primary cell, a dry cell contains paste of an electrolyte instead of the solution. The contents of electrolyte paste react with each other through a chemical process and convert the chemical energy into electrical energy.
Not my answer but nevertheless
Answer:
Electric potential develops in primary/dry cells through a chemical reaction between the cell plates of the cell. free electrons move from the zinc plate to the copper plate through a conducting material.
Electric potential develops in Generators via magnetic induction i.e. the movement of a conducting rod through the magnetic field between the poles of the horseshoe magnets produces Electric potential in Generators.
Electric potential develops in thermocouples via heat transfer ; A heat source is applied to the connecting end of the thermocouple strips and this will cause the production electric charges ( potential ) at the free ends
3) Identifying effect of each scenerio
a) The resistance of an electric current will increase when the length of the conductor increases
b) The resistance of an electric current through a body will decrease when the conductor has a larger cross-section
c) The resistance of an electric current through a body will decrease when the temperature of the conductor is cooled
4) The amount of heat lost as heat in Btu = 2.73 Btu
amount of heat lost = 0.8 Wh
convert to Btu = 0.8 Wh / 0.293 = 2.73 Btu ( note : 1 Btu = 0.293 Wh )
5) The amount of of energy used by a 40 W bulb for 365 days = 146 kWh
Power of bulb = 40 W
Run time = 10 hours * 365 days
∴ amount of energy used = 3650 * 40 = 146 * 10^3 Wh = 146 kWh
