Which energy conversion takes place when a solar cell is used to light a street lamp?

Carbon-14 is a radioactive element that undergoes beta decay. which force is responsible for allowing carbon-14 to become stable? electromagnetic gravitational weak nuclear strong nuclear

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.

Am i correct on these two physics questions?