Capstone Revision 3

At 270 degrees in its rotation a generator is producing what value of AC current?

• + RMS

• - RMS

• + Peak Value

• - Peak value

The periodic time of a 25Hz waveform is how many ms?

• 4ms

• 10ms

• 16ms

• 8ms

When 3 phase AC is generated by how many degrees is the phase shift between phases?

• 90 degrees

• 120 degrees

• 180 degrees

• 270 degrees

The frequency output of a generator is directly related to what?

• The speed of the rotor

• The number of poles in the generator

• The speed of the rotor and the number of field windings

• The speed of the rotor and the number of poles in the generator

In a generator a magnetic field is rotated inside a stationary filed so that the __________? flux cuts across the stationary conductors.

• Magnetic

• Induced

• Electrical

• voltage

In hydro generation the amount of water entering the turbine is controlled by “wicket gates”. Why is this required?

• It controls the generator output current

• Its how the output voltage is controlled

• To limit the mechanical forces on the rotating turbine

• Its how the speed of the rotating turbine is controlled and thus the frequensy

A single solar cell on a solar produces approximately how many volts?

• 0.5v dc

• 0.8v dc

• 5v dc

• 6v dc

The main advantage of using AC for the transmission of voltage around NZ is what?

• Less losses than DC

• Can transmit large amonts of power over long distances at less cost

• The ease that it an be stepped up or down for transmission purposes

• Less capacitve reactance losses the DC

Hydro generation converts the kinetic energy of water into __________? energy

• Rotational

• Gravitational

• Inductive

• Electrical

Grid connected photovoltaic systems are usually set at a tilt angle of how many degrees?

• Local latitude plus 10 degrees

• Local longitude minus 10 degrees

• Local longitude plus 10 degrees

• Local latitude minus 10 degrees