what is meant by (a) a complete circuit and (b) an open circuit?
The correct answer and explanation is:
Correct Answer:
(a) A complete circuit is a closed loop that allows electric current to flow from a power source, through a load or device, and back to the power source.
(b) An open circuit is a broken or incomplete path that prevents the flow of electric current.
Explanation:
A complete circuit is essential for the flow of electricity. It includes a power source (like a battery), conductors (such as wires), and a load (like a light bulb or motor) that uses the electrical energy. When all the components are properly connected, the electric current flows continuously through the loop. In a complete circuit, electrons travel from the negative terminal of the power source, move through the conductor, pass through the load where electrical energy is converted into another form (like light or motion), and return to the positive terminal. This continuous path ensures that energy reaches the load and makes the device function.
A simple example of a complete circuit is a flashlight. When the switch is turned on, it connects all the internal components and forms a closed loop. This allows the battery to supply power to the bulb, which then lights up.
An open circuit means the path is broken at some point. It might be due to a switch being turned off, a broken wire, or a disconnected component. In an open circuit, the flow of electrons is interrupted, so no current passes through the load, and the device does not operate. The circuit is incomplete, and the power cannot reach the destination.
For instance, if the switch on a flashlight is off or the batteries are not inserted properly, the circuit is open. No electricity flows, so the bulb does not light. Open circuits are useful when one wants to stop the flow of current, such as turning off lights or appliances.