Question

Electric appliances with metallic body e.g., heaters, presses etc., have three pin connections, whereas an electric bulb has a two pin connection. Three pin connections reduce heating of connecting cables.

• A. If both A and and Reason are true and Reason is the correct explanation of Assertion
• B. If both Assertion and Reason are true but Reason is not the correct explanation of Assertion
• C. If Assertion is true but Reason is false
• D. If Assertion is false but Reason is true

Answer 1

Answer: (C)

If Assertion is true but Reason is false

Answer 2

The buoyancy of an object is the resultant of all the contact forces that are present at the points of contact of the body and hence the force of buoyancy depends upon the area of contact of the body with the fluid. The force of buoyancy is more in case of the needle than in the case of the ball. Now it might so happen that the force of buoyancy $(B)$ is greater than the weight $(m g)$ of the needle, in which case the needle might float. But in the case of the ball, $B< m g$, and so the ball sinks.