Question

Assertion: Some electric appliances have three pin, even though if we remove the top pin, it will continue working.
Reason: The third pin is used only as a safety device.
A. Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
B. Both Assertion and Reason are correct and Reason is not the correct explanation of Assertion.
C. Assertion is correct but Reason is incorrect.
D. Both Assertion and Reason are incorrect.

Answer 1

Hint:Recall the construction of a plug pin consisting of three pins in it. Mention the work of each pin connected in this three pin plug and check which of the pins in this plug are connected to the circuit in the electrical appliance. Hence, determine if one removes the top pin from the plug, whether the appliance works as before and hence check the purpose of using this third pin in the plug.

Complete answer:
We know that the plug of some electrical appliances consist of three pins. The three pins if this plug has three wires connected to it and these wires connected in the plug pin are live wire, neutral wire and earth wire.The live wire (generally brown in color) and neutral wire (generally blue in color) together form a complete circuit and provide the electrical appliance the electric current required for its working.

The earth wire (generally yellow and green in color) does not contribute to the circuit of the electrical appliances. Hence, if we remove the third earth wire which is at the top of the pin, the electrical appliance will continue working normally as the electric current is supplied to the circuit in the appliance as before.Hence, the Assertion is correct.

The third earth wire which is at top of the plug pin, is connected to the ground and the ground is considered ideally at zero potential.If there is breaking of any wire in the circuit of the electrical appliance then the electric current may starts flowing in the appliance and one may receive shock while working with it.

In such cases, the third earth wire in the plug pin transfers all the current to the ground which is at zero potential and the person using the appliance is prevented from a large electrical shock.Thus, the third pin is used for the safety reason.Hence, the Reason is also correct.So, both Assertion and Reason are correct and Reason is the correct explanation of Assertion.

Hence, the correct option is A.

Note:The students may think that the third pin in the plug consisting of the earth wire does not seem connected to the ground then why we are saying that it is grounded to the Earth. But the students should keep in mind that this third wire is connected to the ground through the electrical appliance and not the plug pin.