Apoint charge of −3.50 µc is located in the center of a spherical cavity of radius 5.00 cm inside an insulating charged solid. the charge density in the solid is ρ = 7.35 × x10−4 c/m3 . calculate the electric field inside the solid at a distance of 10 cm from the center of the cavity.

If the heat engine is a perfect carnot cycle engine, thenefficiency = (t2-t1)/t2   where t1=temperature of cold reservoir ( ° k) = 135            t2=temperature of hot reservoir ( ° k)   = 325thereforeefficiency = (t2-t1)/t2 = (325-135)/325 = 0.5846 = 58%  note: this is the theoretical maximum efficiency of a perfect heat engine.   real-life engines do not achieve this value.