Physics
A student connects a bulb to a cell using two wires, but the bulb does not glow. On checking, the bulb is found to be in proper condition. On further inspection, a wire is found to be loose.
(a) Why did the bulb not glow even though it was not faulty?
(b) What is meant by a closed circuit?
(c) Why is electric current considered as a flow of charges?
(d) What is the conventional direction of electric current?
Current Electricity
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Answer
(a) The bulb did not glow because the circuit was incomplete (open circuit) due to the loose wire, so even though the bulb was fine, current could not flow without a continuous conducting path.
(b) A closed circuit is a complete and continuous path through which electric current can flow from the cell, through the components and back to the cell.
(c) Electric current is considered as a flow of charges because it is defined as the rate of flow of electric charge. In conductors, this charge is carried by electrons.
(d) The conventional direction of electric current is from the positive terminal to the negative terminal of a cell, opposite to the actual flow of electrons.
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