Science : Ch 12 – Electricity

Ammeter is a device used for measuring electric current in amperes

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

Three resistors of 2 Ω is required to get 6 Ω because resultant is more than individual so they all must be connected in series.

Total power used, P = P1 + P1 = 1500 + 500 = 2000 W.Current drawn from the supply,

Ammeter at the times connected in series with in the circuit. The reading is independent from its location.

Q = ne and Q = It∴ ne = It

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 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.

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.

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.