Deck 5: Powers and Roots

Question 1

How many volts are required if the power is 25 watts and the resistance is 64 ohms?

Answer 1

40

Question 2

The square of the diameter equals the cross-sectional area. Find the cross-sectional area in the circular mils of a wire that is 104 mils in diameter.

Answer 2

10,816

Question 3

When the resistance is 73.3 ohms and the power is 165 watts, what is the value of the current in amperes? Carry answer to two decimal places.

Answer 3

1.50

Question 4

An electrical cable has a cross-sectional area (CM) of 1,000,000 circular mils and contains 19 strands. Find the diameter (d) of each strand using . Carry the answer to two decimal places.

Question 5

When using a Texas Instruments TI 36X calculator, to activate the scientific notation mode press the following keys:

A) 2^nd function key and X²
B) 2^nd function key and 5 key
C) 3^rd function key and 6 key
D) 3^rd function key only

Question 6

If a 250,000 circular mil cable is composed of 37 strands, what is the approximate diameter of each strand? Carry the answer to two decimal places.

Question 7

If [30][X²][=] is entered in a calculator the display will show:

A) 60
B) 900
C) 30
D) 30 x 30

Question 8

The square of the diameter equals the cross-sectional area. A cable is checked for a power job and is found to be too small. The cable contains 62 strands of copper wire that each have a diameter of 37.2 mils. What is the size of the cable in circular mils? Carry the answer to two decimal places.

Question 9

Using the reciprocal key on a calculator, the reciprocal of 4 is:

A) 4.0
B) 4.4
C) 0.4
D) 0.25

Question 10

If a calculator does not contain an n^th root key, the n^th power key can be used by raising the number to the reciprocal of the power.

Question 11

If a 5,000,000 circular mil cable is composed of 37 strands of copper wire of equal size. What is the approximate diameter of one strand? Carry the answer to two decimal places.

Question 12

When the power is 220 watts and the resistance is 100 ohms, what voltage is in the circuit? Carry the answer to two decimal places.

Question 13

Find the number of volts in the circuit if the resistance has a value of 22 ohms and uses 550 watts.

Question 14

When a number must be squared, the square key symbol on a calculator is:

A) X²
B)
C)
D)

Question 15

The square root key on a calculator looks like:

A)
B) n²
C) X²
D)

Question 16

The number of watts used in a circuit is equal to the volts squared divided by the ohms. Find the wattage used in the circuit shown. Round the answer to the nearer tenth.

Question 17

A calculator is set in the Engineering mode. The display shows: 56.345 -03. Express this value in the proper engineering units.

A) 56.345 micro
B) 56.345 milli
C) 5.6345 milli
D) 563.45 milli

Question 18

A cable is checked for a power installation and is found to be too small. The cable has 37 strands of copper wire, each having a diameter of 82.2 mils. Find the size of the cable in circular mils. Carry answer to two decimal places.

Question 19

If the resistance has a value of 550 ohms and uses 22 watts of power, find the number of amperes of current that the resistance takes. Carry the answer to one decimal place.

Question 20

To find the number of watts used in any circuit, the amperes squared are multiplied by ohms. Find the number of watts for the device shown. Carry the answer to two decimal places.

Question 21

A scientific calculator is set to operate in the Floating Decimal mode (Flo). The calculator display shows 945635.045. Now set the calculator to Engineering mode (Eng). What would the display show?

Question 22

A radio signal is measured at 150 microvolts ( ). Express this as volts.

Question 23

An industrial plant is supplied with high voltage power from the power company. The power lines are rated 13.8 kV. Express this value as volts.

Question 24

If the cross-sectional area in a circular mils of a wire is 4.107, what is the diameter in mils? Carry the answer to two decimal places.

Question 25

A 2,583-circular-mil cable is composed of 25 strands of copper wire of equal size. What is the approximate diameter of one strand? Round the answer to the nearest tenth.

Question 26

480 volts is connected to an 18-ohm resistive-heating element. How much power is being produced by the heating element? Carry the answer to three decimal places.

Question 27

The resistance of a coil that uses 800 watts is 62 ohms. What is the voltage of the circuit? Round the answer to the nearest hundredth.

Question 28

Use one space between the number and the scientific notation exponent. A scientific calculator is set to operate in the Floating Decimal mode (Flo). The calculator display shows 945635.045. If the calculator is changed to operate in the Scientific mode (Sci), what would the display show?

Question 29

A 24-ohm resister has a current of 0.65 amperes flowing through it. How much power is being produced by the resister? Carry the answer to two decimal places.