IBEW Ratio and Proportion 3

Question 1

The ratio of the length to width of a rectangular electrical panel cover is 5:2. If the width is 14 inches, what is the length?

Accepted Answer

35 inches

Answer

28 inches

Answer

30 inches

Answer

40 inches

Question 2

An electrical plan calls for 3 outlets for every 150 square feet of floor space. How many outlets are needed for a 1,200 square foot area?

Accepted Answer

24

Answer

18

Answer

20

Answer

28

Question 3

If the resistance of wire is directly proportional to its length, and 200 feet of wire has a resistance of 5 ohms, what is the resistance of 350 feet of the same wire?

Accepted Answer

8.75 ohms

Answer

7.25 ohms

Answer

7.75 ohms

Answer

9.25 ohms

Question 4

A union job requires 1 foreman for every 7 workers. If there are 56 workers on the site, how many foremen are required?

Accepted Answer

8

Answer

6

Answer

7

Answer

9

Question 5

Materials for a job cost $420 and cover 280 square feet. How much will materials cost to cover 350 square feet at the same rate?

Accepted Answer

$525

Answer

$490

Answer

$510

Answer

$540

Question 6

A conduit system uses a 4:1 ratio of horizontal runs to vertical runs. If there are 80 feet of horizontal conduit, how many total feet of conduit are in the system?

Accepted Answer

100 feet

Answer

90 feet

Answer

95 feet

Answer

120 feet

Question 7

A transformer steps voltage up in a 10:1 ratio. If the primary (input) coil has 500 turns and the secondary has 5,000 turns, and the input voltage is 120 volts, what is the output voltage?

Accepted Answer

1,200 volts

Answer

600 volts

Answer

900 volts

Answer

1,500 volts