Assertion (A) : The steam engine was invented by James Watt.
Reason (R) : There was a problem of taking out water from flooded mines.

A. BOTH A AND R ARE TRUE AND R IS THE CORRECT EXPLANATION OF A.

Choose the correct alternative from the following : - Assertion (A) : The Indian Constitution came into force with effect from 26th January, 1950.
Reason (R) : 26th January is celebrated as the Republic Day.

B. BOTH A AND R ARE TRUE BUT R IS NOT THE CORRECT EXPLANATION OF A.

Choose the correct alternative from the following : - Assertion (A) : Copper is used to make electric wires.
Reason (R) : Copper has very low electrical resistance.

A. BOTH A AND R ARE TRUE AND R IS THE CORRECT EXPLANATION OF A.