Electricity is the flow of electric charge that powers devices and makes things work.
Important Parts of Electricity:
- Electric Current: The flow of electric charge, measured in Amps (A).
- Voltage: The force that pushes the electric charge, measured in Volts (V).
- Resistance: The opposition to the flow of current, measured in Ohms (Ω).
- Ohm's Law: V = I × R – Voltage = Current × Resistance.
- Power: The amount of energy used, calculated by P = V × I (measured in Watts).
Types of Current:
- DC (Direct Current): Flows in one direction (like from a battery).
- AC (Alternating Current): Reverses direction (like in home electricity).
Practice Questions PDF
Download a printable worksheet on Electricity with answers.
Questions on Electricity
Showing 121–128 of 128121.A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross section of the filament in 16 seconds would be roughly. 122.Calculate the resistivity of the material of a wire of length 1 m, radius 0.01 cm and resistance 20 ohms. 123.List the factors on which the resistance of a conductor in the shape of a wire depends. 124.Why are alloys commonly used in electrical heating devices ? 125.Why are metals good conductors of electricity whereas glass is a bad conductor of electricity ? Give reason. 126.Calculate the resistance of a metal wire of length 2 meters and cross-sectional area 1.55 × 10⁻⁶ square meters, if the resistivity of the metal is 2.8 × 10⁻⁸ ohm meter. 127.How is the resistivity of alloys compared with those of pure metals from which they may have been formed? 128.Name a device that you can use to maintain a potential difference between the ends of a conductor. Explain the process by which this device does so.