Understanding the 18th Edition Wiring Regulations Quiz

What is the difference between impedance and resistance in the context of electrical circuits?

• Impedance is measured on a live circuit with alternating current, while resistance is measured on dead circuits with direct current

• Impedance is measured on dead circuits with direct current, while resistance is measured on live circuits with alternating current

• Impedance is measured in ohms, while resistance is measured in volts

• Impedance is measured in volts, while resistance is measured in ohms

What does a lower impedance value indicate in terms of electrical circuits?

• A lower impedance value indicates a higher chance of electric shock

• A lower impedance value indicates a slower disconnection time

• A lower impedance value indicates a greater fault current

• A lower impedance value indicates a smaller fault current

Where can the maximum permitted disconnection time for different nominal voltages and earthing systems be found?

• Table 41.6 on page 68

• Table 41.2 on page 61

• Table 41.3 on page 62

• Table 41.4 on page 63

What is the maximum permitted zs value for a type b bs en 60898 circuit breaker of 32 amps?

• 0.60 ohms

• 1.37 ohms

• 2.50 ohms

• 3.00 ohms

What is the maximum permitted disconnection time for a distribution circuit with a type c bs en 60898 circuit breaker in a 63.5 volt system?

• 2.50 seconds

• 5.00 seconds

• 1.00 second

• 0.40 seconds

What is the maximum permitted zs value for a bs 88-3 fuse rated at 32 amps in a distribution circuit?

• 0.60 ohms

• 2.50 ohms

• 3.00 ohms

• 1.37 ohms

What does the c min factor of 0.95 in the context of zs values represent?

• An adjustment for circuit resistance

• An adjustment for current flow

• An adjustment for voltage fluctuations

• An adjustment for temperature changes

Where can one find the information about zs and disconnection times in the wiring regulations book?

• Page 3

• Page 41

• Page 68

• Page 59