Entropy measures
a. disorder
b. energy
c. heat transferred
d. force

The correct option is (a).

Explanation:

Entropy measures the degree of the randomness or disorder. Entropy increases with the increase in the temperature.

If the volume of the system increases then the entropy will also increase. As the degree of the randomness of the system increases in the expansion of the volume.

Therefore, entropy measures disorder.

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000