Answer is:
Henri Becquerel
Explanation:
Natural radioactivity was discovered by henry baquerel.
Answer is:
non-luminous heavenly bodies
Explanation:
Planets don't have their own light so they are said to be non-luminous.
Answer is:
a good conductor of heat but a bad conductor of electricity
Explanation:
Its true, that mica is a good conductor of heat but a bad conductor of electricity, mica heats the iron's base but not give electric shock. That's why it is use in electric iron.
Answer is:
the rolling friction is much less than the sliding friction
Explanation:
The energy used in rolling the fuel tank on the coal tar is much less because in pulling the fuel tank via an inclined plane the frictional force to be overcome will be greater than rolling it down the plane.