Edge - Flashed Q&A []

EDGE – EE FLASHED Q&A When an armature opens in dc motor, it may cause Ans: intermittent sparking Considered as a variable speed motor Ans: series A cell that cannot be recharged is Ans: a primary cell This applies to a nonradiative transition of an atom from an excited energy state to a lower energy state, accompanied by the emission of an electron

In applications where sudden heavy loads happen for short duration, a ______ motor is the best choice. Ans: cumulatively compounded When a motor is overloaded, it will Ans: overheat What instrument is used to measure the intensity of radiation, such as by determining the amount of fluorescence produced by that radiation Ans: actinometer

Ans: Auger effect

Where would you most likely find a lead-acid battery

Motors whose speed can be easily controlled

Ans: in a portable video camera/recorder.

Ans: dc motors

Electrical machine that changes ac voltage at one frequency to another ac voltage at another frequency

To minimize arcing during starting of dc motors, a resistance should be added to limit the current in the ______

Ans: frequency converter

Ans: armature winding

Factor[s] that affect iron losses in a dc motor

A disadvantage of mercury cells and batteries is

Ans: flux and field are correct

Ans: they pollute the environment

In motors of the same rating, which has the least starting torque

Synchronous-type ac motor Ans: uses a dc generator to supply a dc excitation to the rotating field A motor whose speed increases as the load is increased Ans: differentially compounded

Ans: dc shunt The electron beam in an electrostatic CRT is bent by Ans: an electric field produced by charged electrodes

The meter movement in an illumination meter measures Ans: current

In a perfect sie wave, the peak-to-peak value is Ans: twice the peak value An inductor works by

The maximum voltage output from a voltage divider

Ans: storing energy as a magnetic field

Ans: is equal to the supply voltage

A typical frequency counter

Carbon composition resistor

Ans: is usually accurate to 6 digits or more

Ans: are comparatively nonreactive A metal-film resistor Ans: has less reactance than a wire-wound type Advantage of a rheostat over a potentiometer is that Ans: rheostat can handle more current A Weston cell is generally used Ans: as a voltage reference source A direct short-circuit of a battery can cause Ans: an explosion The energy in a cell or battery depends mainly on Ans: its physical size An interactive solar power system Ans: allows a homeowner to sell power to the utility The geomagnetic field Ans: is what makes a compass work An ac electromagnet Ans: will attract pure, unmagnetized iron