EWRB THEORY: Electrical Workers Registration Board
- Questions & Accurate Answers
What does BJT stand for? Right Ans - Bipolar Junction Transistor
What does the transducer do? Right Ans - converts energy from one form
to another
State one factor that determines voltage drop Right Ans - Length of cable
State one reason why a class 1 electrical appliance is set at a maximum of 1
ohm Right Ans - It prevents the touch voltages rising to dangerous levels
State the test voltage used for carrying out an insulation resistance test.
Right Ans - 500V DC
What is the name of the system where neutral conductor is connected to the
earth at the main switchboard Right Ans - MEN System
State one reason why HRC fuses are installed at the origin of the final sub
circuit supplying the induction motor Right Ans - To provide short circuit
fault protection to both the final sub circuit and the motor
State one reason why an RCD tester is used to test a PRCD Right Ans - To
verify the PRCD operates within the specified residual current
State the main safety issue that would occur if the only testing done was
between each phase on a 400V oven Right Ans - One phase could still be
live
What potential danger would transposition of phased and neutral in an
isolating switch create. Right Ans - Phase would still be live when the
isolation switch is in the off position
Name two types of earth electrodes that made be used to connect an MEN
System to the mass of earth Right Ans - Earth rod
Earth mat
- Questions & Accurate Answers
What does BJT stand for? Right Ans - Bipolar Junction Transistor
What does the transducer do? Right Ans - converts energy from one form
to another
State one factor that determines voltage drop Right Ans - Length of cable
State one reason why a class 1 electrical appliance is set at a maximum of 1
ohm Right Ans - It prevents the touch voltages rising to dangerous levels
State the test voltage used for carrying out an insulation resistance test.
Right Ans - 500V DC
What is the name of the system where neutral conductor is connected to the
earth at the main switchboard Right Ans - MEN System
State one reason why HRC fuses are installed at the origin of the final sub
circuit supplying the induction motor Right Ans - To provide short circuit
fault protection to both the final sub circuit and the motor
State one reason why an RCD tester is used to test a PRCD Right Ans - To
verify the PRCD operates within the specified residual current
State the main safety issue that would occur if the only testing done was
between each phase on a 400V oven Right Ans - One phase could still be
live
What potential danger would transposition of phased and neutral in an
isolating switch create. Right Ans - Phase would still be live when the
isolation switch is in the off position
Name two types of earth electrodes that made be used to connect an MEN
System to the mass of earth Right Ans - Earth rod
Earth mat
