GROL General Radiotelephone

Question 1

What formula would determine the inductive reactance of a coil if frequency and coil inductance are known?

Accepted Answer

XL = 2πf L

Answer

XL = πf L

Answer

XL = 1 / 2πf C

Answer

XL = 1 / R2+X2

Question 2

Permeability is defined as:

Accepted Answer

The ratio of magnetic flux density in a substance to the magnetizing force that produces it.

Answer

The magnetic field created by a conductor wound on a laminated core and carrying current.

Answer

Polarized molecular alignment in a ferromagnetic material while under the influence of a magnetizing force.

Answer

None of these.

Question 3

Which of these will be most useful for insulation at UHF frequencies?

Accepted Answer

Mica

Answer

Rubber

Answer

Wax impregnated paper

Answer

Lead

Question 4

Which of the 4 groups of metals listed below are the best low-resistance conductors?

Accepted Answer

Gold, silver, and copper

Answer

Stainless steel, bronze, and lead

Answer

Iron, lead, and nickel

Answer

Bronze, zinc, and manganese

Question 5

How does the input impedance of a field-effect transistor compare with that of a bipolar transistor?

Accepted Answer

A FET has a high input impedance; a bipolar transistor has a low input impedance.

Answer

One cannot compare input impedance without first knowing the supply voltage.

Answer

An FET has a low input impedance; a bipolar transistor has a high input impedance.

Answer

The input impedance of FETs and bipolar transistors is the same.

Question 6

What is the description of a square wave?

Accepted Answer

A wave that abruptly changes back and forth between two voltage levels and stays at these levels for equal amounts of time.

Answer

A wave with only 300 degrees in one cycle.

Answer

A wave whose periodic function is always negative.

Answer

A wave whose periodic function is always positive.

Question 7

Which of the following groups is correct for listing common materials in order of descending conductivity?

Accepted Answer

Silver, copper, aluminum, iron, and lead

Answer

Lead, iron, silver, aluminum, and copper

Answer

Iron, silver, aluminum, copper, and silver

Answer

Silver, aluminum, iron, lead, and copper

Question 8

Which of the following Ohm Law formulas is incorrect?

Accepted Answer

I = R / E

Answer

I = E / R

Answer

E = I x R

Answer

R = E / I

Question 9

The second harmonic of a 380 kHz frequency is:

Accepted Answer

760 kHz

Answer

2 MHz

Answer

190 kHz

Answer

144.4 GHz

Question 10

At 150 degrees, what is the amplitude of a sine wave having a peak value of 5 volts?

Accepted Answer

+2.5 volts

Answer

-4.3 volts

Answer

-2.5 volts

Answer

+4.3 volts