Review for 3B midterm

If a three-phase load is a pure reactive load, then the power calculated has units of _____.

VARs

When calculating the power of a pure resistive load, the voltage and current are in phase with each other and the power factor is _____.

one

A delta-wye transformer has its _____ connected as a delta and its _____ connected as a wye.

primary; secondary

In a wye-connected system, the line voltage is higher than the phase voltage by a factor of _____.

the square root of three

A tape-wound core is also called a(n) _____ core.

toroid

In an open delta with single-phase loads, the high leg must be identified by _____.

using orange wire AND/OR tagging

When connecting three transformers for three-phase use with a delta secondary, a voltage test should be done before closing the secondary. The correct voltage reading is _____.

zero volts

_____ currents are small independent currents that are produced as a result of the expanding and collapsing magnetic field. They flow erratically within the conductor opposing current flow and consuming power.

eddy

Any transformer flux that does not follow the core and escapes into the surrounding air is called _____.

flux leakage

An isolation transformer has the same _____ and ____ voltages.

input; output

A transformer is a(n) operated device that can change values of voltage, current, and impedance without changing frequency?

magnetically

In three-phase power systems, the delivered power _____.

never falls to zero