Science : Ch 12 – Electricity

An ampere is the SI unit of electric current

Work done in transferring the charge W= qV = qlR …….. (V = IR)

In parallel combination, voltage remains same across two points

Current is inversely proportional to the resistance for the same potential. So higher resistance would allow less current to pass through its which is shown by R3 as I3 < I2 < I1∴ R3 >R2 > R1

The gap between conduction band and valence band is much greater than conductors which don't allow them to conduct electricity very easily which in result shows greater resistance, so insulators offer infinitely high resistance.

electrons move from low potential to high potential. Note: So, the end of high potential has more positive charges and the end of the battery with low potential has more negative charges. While the electric current flows from the high potential to the low potential.

Ohm's law states that the electrical current (I) flowing in an circuit is proportional to the voltage (V) and inversely proportional to the resistance (R). Therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change.

repulsion is noticed only when two bodies have like charges and this means that the bodies must be charged. Hence, repulsion is a true test of electrification

one horse power is determined as almost 746 Watt in standard calculations. It derived its name from the following context: One horsepower is the amount of power used by a horse to lift a 550 pounds heavy object from a depth of 1 foot in one second. This power when converted to SI system gives 746 Watts.

A kilowatt-hour is an amount of energy consumed by a machine working at a steady rate of one kilowatt for one hour. As a result, Joule is a SI unit of energy, but Kilowatt-hour is a Commercial unit.