Which of the following devices is used to convert alternating current into direct current?

Correct option is D

The correct answer is (d) Rectifier.

Explanation:

• A rectifier is an electrical component that converts alternating current (AC) to direct current (DC).
• A rectifier is analogous to a one-way valve that allows an electrical current to flow in only one direction.
• The process of converting AC current to DC current is known as rectification.
  

Information Booster:

• A calorimeter is a device that measures the heat produced or absorbed during a chemical or physical process. It's used in chemistry, physics, and biochemistry to study thermodynamics and the heat capacity of substances.
• A rheostat is a device that is used to adjust the resistance in an electric circuit. A rheostat is a variable resistor that allows the manual control of the flow of electric current by lowering or raising the resistance. When a rheostat is used in a circuit, the flow of electric current can be controlled.
• A capacitor is a passive, electrical component that has the property of storing electrical charge, that is, electrical energy, in an electrical field. In basics, the capacitor consists of two electrodes, which are separated by a dielectric.