Which device is used to either break electric circuit or to complete it?

The correct answer Switch.

Key Points

• A switch is a simple device that is used to either break the electric circuit or complete it.
• A resistor is a passive electrical component that resists the flow of electric current.
• A transistor is a semiconductor device that acts as both an amplifier and a switch.
• A fuse is an electrical device for safety that removes electrical current from the circuit if the current gets too high.

Additional Information

• Transistors:
  • Transistors are semiconductor devices, which are commonly used in amplifiers or electrically controlled switches
  • Transistors are the basic building block that regulates the operation of computers, mobile phones, and all the other modern electronic circuits
  • The most important transistor function is as a current amplifier and as a switch
  • Transistors as current amplifiers are often used in amplifiers while transistors as switches are often found in automatic light circuits
  • The functions of a transistor are variable resistors and switching devices.
• Capacitor:
  • ​A capacitor is a device that stores electrical energy in an electric field.
  • It is a passive electronic component with two terminals.
  • The effect of a capacitor is known as capacitance.
  • Capacitance: The capacitance is the capacity of the capacitor to store charge in it.
  • Two conductors are separated by an insulator (dielectric) and when an electric field is applied, electrical energy is stored in it as a charge.
    • The capacitance of a capacitor (C): The capacitance of a conductor is the ratio of charge (Q) to it by a rise in its potential (V), i.e.
    • C = Q/V
• ​Resistor:
  • A resistor is a passive element.
  • It is represented by ‘R’ and is measured in ohms (Ω).
  • Resistors are used to reduce current flow, adjust signal levels, to divide voltages.