EPC5 - Operation of Practical Circuits Flashcards
What are the THREE basic parts of any electrical circuit?
A basic circuit consists of a voltage source, conductors and a device for using the electricity (a load).
A typical practical electrical circuit can consist of three BASIC components and two additional ones. What are the two additional components?
The two additional components are a means of controlling the circuit (e.g. a switch) and a protective device (e.g. a fuse).
What is the purpose of a Fuse or Circuit Breaker in an electrical circuit?
The purpose of a fuse is to automatically disconnect the supply in the event of a short circuit to earth, or between active and neutral.
At what approximate current would a 10A circuit breaker trip?
A 10A circuit breaker should trip at 14.5A (1.45 x rating B3.2.1).
What essential safety precaution must be taken before attempting to replace a fuse or re-set a circuit breaker?
Isolate the supply.
What is the name of the most common type of cartridge fuse for high current circuits?
An HRC (high rupturing capacity) fuse.
What electrical value stays the same in all parts of a series circuit?
The line current
What electrical value stays the same in all parts of a parallel circuit?
The voltage across each component.
State the definition for Kirchhoff’s Voltage Law.
The sum of the potential differences in a series circuit must be equal to the voltage applied to the series circuit
State the definition for Kirchhoff’s Current Law.
The sum of the currents flowing towards a junction is equal to the sum of the currents flowing away from that junction.
What does Ohm’s Law state?
The current in a circuit is directly proportional to the applied voltage, and inversely proportional to the resistance in that circuit, at a given temperature.
