The answer is B. Capacitor.
A capacitor is an electrical device that can store an electric charge. It consists of two conductive plates separated by an insulating material called a dielectric. When a voltage is applied to the capacitor, the charge builds up on the plates. The amount of charge that can be stored depends on the capacitance of the capacitor, which is measured in farads.
An inductor is a coil of wire that stores energy in a magnetic field. When current flows through the inductor, a magnetic field is created. The strength of the magnetic field depends on the amount of current flowing through the inductor.
A transistor is a semiconductor device that can be used to amplify or switch electronic signals. It consists of three semiconductor regions: the emitter, base, and collector. The transistor works by controlling the flow of current between the emitter and collector regions.
A relay is an electromagnetic switch that is used to control a circuit by opening or closing a switch. It consists of a coil of wire that is wrapped around an iron core. When current flows through the coil, a magnetic field is created. The magnetic field attracts a lever, which opens or closes a switch.
In conclusion, the answer to the question “Which consists of two plates separated by a dielectric and can store a charge?” is B. Capacitor.