Official CBT1

How is the armature in a dc generator connected to an external circuit?

• Through slip rings

• Through a resistor

• Through a commutator

• Through a fixed contact

What current does a short circuit produce?

• Zero current

• Steady current

• Overload current

• Excessive current

What is the relationship between Work and Force?

• Force = Work x Time

• Force = Work ÷ Time

• Work = Force ÷ Distance

• Work = Force x Distance

What effect produces a force of attraction when current is passed through a relay coil?

• Heating

• Magnetic

• Radiation

• Chemical

What process does a fuel cell use to produce electrical energy?

• Heat reaction

• Magnetic action

• Chemical reaction

• Photovoltaic action

What is the function of a potentiometer?

• To produce a magnetic field

• To provide variable voltages

• To provide a heating element

• To add fixed resistance into a circuit

What is the relationship for stored energy in a capacitor?

• ½ CV²

• 2 CV²

• ½ C²V

• 2 C²V

A voltmeter across a load reads 100 V and an ammeter indicates a load current of 2.5 A. What is the resistance of the load?

• 25 Ω

• 40 Ω

• 250 Ω

• 400 Ω

Which statement describes the correct procedure when terminating cables?

• Insulation is removed using pliers

• Leave 20 mm of exposed bare conductor at a termination

• All strands of a conductor do not need to enter an electrical connection

• Green/yellow insulation must cover bare protective conductors at terminations

Which safety precaution must be taken when using a bench grinder?

• The wheel must run for one minute before use

• Goggles only need to be worn for grinding steel

• The wheel must rotate freely before switching on

• The rest must be at least 10 mm away from the wheel