ENGR 200 FALL 2016 P4: POWER LOSS IN A TRANSMISSION LINE

(if statements, loops)

DUE: October 6, 2016 by 11:59 p.m. CT (extra credit)

October 11, 2016 by 11:59 p.m. CT (final deadline) POINTS: 50 INTRODUCTION:

When electricity is transmitted through voltage lines, losses occur due to electrons colliding, converting their

energy into heat. To minimize these losses, generally current is transmitted over long distances at high voltage;

higher currents lead to heat losses, and low currents require high voltage (Ohm’s law). These losses scale with the

square of a wire’s current. (As a note: this is why AC current is used in power transmission – it is less lossy than

DC current.)

The power loss can be calculated using the following equations:

i= power transmitted∈watts

volts transmitted

R=r∗miles

Power loss=i 2∗R where:

i = current (amps)

r = resistance (ohms/mile)

R = total resistance (ohms)

ASSIGNMENT:

Write a C program that will first allow the user to enter the line resistance in ohms/mile and the power

transmitted in kW. The program needs to ensure that line resistance is between 0.04 and 0.07 ohms/mile and

power transmitted is between 475 and 525 kW; if either of these is not, it should print an error message and the

program should end. If the values are acceptable, the program should compute the power loss for power

transmitted from a station to cities at distances of 15, 30, 45, …, 150 miles at 100 V and 200 V. Use a while loop

to control voltage (initialize at 100.0 and increment by 100.0 to 200.0) and a nested for loop to control distance

(initialize at 15.0 and increment by 15.0 to 150.0). The voltage, distance, and power loss should print to the

screen.

Your program output will look like the illustration shown below. Use your PC’s cursor to determine the

horizontal and vertical spacing for the output format.

NOTE: Use proper variable names. No single letter variables will be accepted. 1 SAMPLE OUTPUT FORMAT:

********************************************

POWER LOSS IN TRANSMISSION LINE

Enter line resistance in ohms/mile: x

Enter transmitted power in kW

:x

RESULTS

Voltage = 100.0 volts

Distance (mi) Power loss (Watts)

15.0

X.XXXEXXXX

30.0

X.XXXEXXXX

45.0

X.XXXEXXXX

60.0

X.XXXEXXXX

.

.

.

.

.

.

150.0

X.XXXEXXXX

Voltage = 200.0 volts

Distance (mi) Power loss (Watts)

15.0

X.XXXEXXXX

30.0

X.XXXEXXXX

45.0

X.XXXEXXXX

60.0

X.XXXEXXXX

.

.

.

.

.

.

150.0

X.XXXEXXXX

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