Question

Assertion: Mass of a body decreases slightly when it is negatively charged.

Reason: Charging is due to the transfer of electrons.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. The assertion is correct but the Reason is incorrect
• D. The assertion is incorrect but the Reason is correct

Answer 1

The correct option is D

The assertion is incorrect but the Reason is correct

Option D: The assertion is incorrect, but the reason is correct

Explantion for the Assertion: Mass of a body decreases slightly when it is negatively charged.

1. The body's electric charge causes it to experience the force when an electric field is applied to it.
2. The mass of the electrons is almost negligible, hence when a negative charge is applied to a body's mass, the electron on the body increases.
3. The charge of an electron is:$$e^{-}=-1.6\times {10}^{-19}C$$., hence now the body will be negatively charged.
4. Electrons have some mass given by : $m=9.1\times {10}^{-31}kg$.
5. So as the number of electrons increases, its mass will also be increased, and henceforth mass of a body will be increased.
6. Hence the Assertion is incorrect.

Explantion for the Reason: Charging is due to the transfer of electrons.

1. Charging anybody is the process of increasing or decreasing the number of electrons.
2. A body becomes negatively charged only when some electrons are transferred to the body, i.e., the body gains some electrons.
3. We know that there are two types of charges:
   Positive charge: when electrons are lost, the body develops a positive charge.
   Negative charge: when electrons are gained, the body develops a negative charge.
4. Because electrons have a negative charge, they become negatively charged when they are added to an object. When electrons are removed from an object, it becomes positively charged.
5. Hence the reason saying, charging is due to the transfer of electrons is correct.

Hence, the assertion is incorrect, but the reason is correct.