ELECTRICAL CIRCUITS (Smart Edge)

If you wish to increase the amount of current in a resistor from 120 mA to 160 mA by changing the 24 V source, what should the new voltage setting be?

• 8 V

• 320 V

• 3.2 V

• 32 V

What is the approximate resistance of a rheostat if the voltage source is 18 V and the current is 220 mA?

• 8.2 kΩ

• 820 Ω

• 8.2 Ω

• 82 Ω

The minimum resistance value for a blue, gray, red, silver resistor is

• 612 Ω

• 6,120 Ω

• 6,800 Ω

• 6,460 Ω

The maximum resistance value for a brown, red, yellow, gold resistor is

• 126,000 Ω

• 126,600 Ω

• 114,000 Ω

• 132,000 Ω

A 33 Ω half-watt resistor and a 330 Ω half-watt resistor are connected across a 12 V source. Which one(s) will overheat?

• 33 Ω

• 330 Ω

• both resistors

• neither resistor

A 15 V source is connected across a 12 Ω resistor. How much energy is used in three minutes?

• 938 Wh

• 0.938 Wh

• 56.25 Wh

• 5.6 Wh

A series circuit consists of a 4.7 kΩ, a 12 kΩ, and a 2.2 kΩ resistor. The resistor that has the most voltage drop is

• the 12 kΩ

• the 2.2 kΩ

• the 4.7 kΩ

• impossible to determine from the given information

All the voltage drops and the source voltage added together in a series circuit is equal to

• the total of the voltage drops

• the source voltage

• zero

• the total of the source voltage and the voltage drops

When an additional resistor is connected across an existing parallel circuit, the total resistance

• remains the same

• decreases by the value of the added resistor

• increases by the value of the added resistor

• decreases

The total resistance of a parallel circuit is 50Ω. If the total current is 120mA, the current through the 270Ω resistor that makes up part of the parallel circuit is approximately

• 22 mA

• 120 mA

• 220 mA

• 50 mA