Transformers are used in the transmission of electrical power to houses.
Which type of transformer is used at the power station prior to connection to the power lines and which type is used prior to delivery to the houses?
power station
before houses
step-down
step-down
step-down
step-up
step-up
step-down
step-up
step-up
C
Electrical energy is transferred by transmission lines at high voltage.
Which statement explains why a high voltage is used?
The voltage is alternating.
The transmission lines have a larger resistance.
The transmission lines carry greater power.
There is a smaller current in the transmission lines for the same power.
D
Electrical power is transmitted at 400 kV and transformed down to 240 V before being delivered to consumers.
Which statement is correct?
A 400 kV cable requires less insulation than a 240 V cable.
Birds are subject to a high-voltage shock when resting on a high-voltage cable.
The current in the transmission wires is equal to the current delivered to the consumers.
With a 400 kV transmission system, a smaller proportion of the energy is used to heat the atmosphere than with a 240 V system.
D