Which instrument converts the alternating current into the direct current? 

The correct answer is Rectifier.

Key Points

• Rectifier:
  • A rectifier is a device that converts an alternating current into a direct current. A p-n junction can be used as a rectifier because it permits current in one direction only.
  • There are types of rectifier i.e. half-wave rectifier and full-wave rectifier.

Additional Information

• Inverter
  • An inverter is a device that changes direct current (DC) to alternating current (AC).
  • The input voltage, output voltage, and frequency.
  • Inverters power the electric appliances in the event of power failure.
  • As the name implies, it first converts AC to DC for charging the battery and then inverts DC to AC for powering the electric gadget.
• ​Capacitor
  • A capacitor is an electrical component that stores energy in an electric field.
  • It consists of two conductors separated by an insulator, also known as a dielectric.
  • The conductors are called plates, and the dielectric is usually a material such as air, paper, or ceramic.
  • The capacitance of a capacitor is measured in farads.
  • The farad is a large unit of capacitance, so most capacitors are measured in microfarads (μF) or picofarads (pF).

• ​Transistor
  • A junction transistor is formed by sandwiching a thin layer of P-type semiconductor between two N-type semiconductors or by sandwiching a thin layer of n-type semiconductor between two P-type semiconductors.
  • NPN transistor: It is formed by sandwiching a thin layer of P-type semiconductor between two N-type semiconductors

• PNP transistor: It is formed by sandwiching a thin layer of N-type semiconductor between two P-type semiconductor.

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