Question Detail
Question
A parallel plate air capacitor with no dielectric between the plates is connected to a constant voltage source. How would capacitance and charge change if a dielectric of dielectric constant K=2 is inserted between the plates? C₀ and Q₀ are the capacitance and charge of the capacitor before the introduction of the dielectric.
Correct Answer
Option D is the correct answer.
Detailed Explanation
When a dielectric material with dielectric constant K is inserted into a capacitor, the capacitance (C) increases by a factor of K.So, C = K * C₀. Given K=2, the new capacitance C = 2C₀.Since the capacitor remains connected to a 'constant voltage source', the voltage (V) across it does not change.The charge (Q) on a capacitor is given by Q = CV.So, the new charge Q = C * V = (2C₀) * V = 2 * (C₀V).Since Q₀ = C₀V, the new charge Q = 2Q₀.Therefore, both the capacitance and the charge double.
Hint
Remember how capacitance changes with a dielectric. Also, note that the voltage remains constant because it's connected to a constant voltage source.