Why is electrical wiring usually made from copper and not silver?
Copper is a better conductor
Copper is a better insulator
Copper is less expensive
Copper is non magnetic
Why is the bulb brighter when it is powered by two cells rather than one?
Because the flow of electricity in the circuit is less
Because the flow of electricity in the circuit is the same
Because the flow of electricity in te circuit is greater.
None of these
Which of the following is the symbol for a bulb?
Rizzvi has connected two bulbs across two cells in a simple circuit.How can he make the bulbs dimmer?
Replace one of the cells with a cork
Replace one of the cells with a wire
Replace one of the bulbs with a cork
Replace one of the bulbs with a wire
Why is electrical wiring usually covered with a layer of plastic?
To make it strong
To help electricity flow in it
To make it safe
To make it beautiful
Which of the following is an electric conductor?
Silver
Cork
Silver coloured plastic
Wood
Pooja makes a simple circuit with one bulb and five cells.The bulb lights for an instant and then goes out.Why?
Electricity could not flow through the circuit
Too much electricity passed through the bulb filament
The wires melted in the heat
All of these
Which of the following appliances does not use an electromagnet?
Fan
Electric bell
Radio
Electric heater
What energy changes take place in the glows with the help of a cell ?
Electrical to light
Electrical to heat to light
chemical to electrical to heat to light
chemical to electrical to light to heat
