Science : Ch 12 – Electricity

An ampere is the SI unit of electric current

W= qV= 20000 × 10 = 2,00, 000 = 2 × 10⁵ J

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

In parallel combination, voltage remains same across two points

The resistance of a bulb increases as the temperature of its filament increases

The resistivity does not change if the shape of resistor is changed because nature of material will remain same.

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.

Constant temperature makes the resistivity constant which made resistance constant. Constant resistance again made the Ohms law applicable. Thats why Ohms law is applied only at constant temperature. It is like the conditions apply of the law.

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.