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Only b was correct.
S1-Q15.) There are two resistors in a parallel circuit. One has the value of 15W in the first branch and the
other is 4W in the second branch. What is the total current if the supply voltage is 15V.

a.) 3.15A
Incorrect.
b.) *4.75A
Correct. RT = 1/(1/15W+1/4W) = 3.16W, I = E/R 15V/3.16W= 4.75Amps.
c.) 11A
Incorrect.
d.) 15A
Incorrect.

S1-Q16.) If a 100W resistor suddenly became open in series circuit, what would happen to the current?

a.) It would become maximum value
Any device that opens in a series circuit will break the current path thus stopping all current flow. It
could never reach its maximum.
b.) *It would become zero
Correct. If the device is open no current can flow in a series circuit.
c.) It would stay the same
If the device is open no current can flow in a series circuit.
d.) It would decrease only slightly .
If the device is open no current can flow in a series circuit.

S1-Q17.) A 10 watt light bulb has 0.5 amps of current running through it. What is the voltage?

a.) 2V
Incorrect. P = I * E or E = P/I, 10/.5 ≠ 2V.
b.) 5V
Incorrect. P = I * E or E = P/I, 10/.5 ≠ 5V.
c.) *20V
Correct. P = I * E or E = P/I, 10/.5 = 20V.
d.) 50V
Incorrect. P = I * E or E = P/I, 10/.5 ≠ 50V.

S1-Q18.) A DMM or Digital Multi-Meter, is used to measure what?

a.) Voltage
Voltage is a function measured by a DMM. However, so is current, resistance, diode levels, (in some
cases) frequency, and several other parameters depending on the brand and model.
b.) Current
Current is a function measured by a DMM. However, so is voltage, resistance, diode levels, (in some
cases) frequency, and several other parameters depending on the brand and model.
c.) Resistance
Resistance is a function measured by a DMM. However, so is current, voltage, diode levels, (in some
cases) frequency, and several other parameters depending on the brand and model.
d.) *All of the above
Correct. Since all of the above mentioned parameters are measured by all DMMs, this is the most
correct answer.

Page 61 - EGSA Apprentice Certification Program Study Guide