1) A parallel plate capacitor of capacitance 90pF is connected to a battery of emf 20 V. If a dielectric material of dielectric constant K=$\frac{5}{3}$ is inserted between the plates ,the magnitude of the induced charge will be A) 1.2nC B) 0.3nc C) 2.4nC D) 0.9nC Answer: Option AExplanation:Magnitude of induced charge is given by Q' = (K-1)CV0 = $(\frac{5}{3}-1)90\times 10^{12}\times 20$ = $1.2\times 10^{-9}C$ $\Rightarrow$ Q'=1.2nC
