Circuits

A 30.-ohm resistor and a 60.-ohm resistor are connected in an electric circuit as shown below. Compared to the electric current through the 30.-ohm resistor, the electric current through the 60.- ohm resistor is

• smaller
• larger
• cannot be determined
• the same 

An electric circuit contains an operating heating element and a lit lamp. Which statement best explains why the lamp remains lit when the heating element is removed from the circuit? 

• The lamp has less resistance than the heating element.
• The lamp has more resistance than the heating element
• The lamp and heating element were connected in parallel.
• The lamp and heating element were connected in series.

A potential drop of 50. volts is measured across a 250-ohm resistor. What is the power developed in the resistor?

• 50 watts
• 10 watts
• 5 watts
• .20 watts

A charge of 5.0 coulombs moves through a circuit in 0.50 second. The current in the circuit is 

• 10A
• 5.0A
• 2.5A
• 7.0A

Which physical quantity is correctly paired with its unit?

• current and amperes/sec
• current and coulombs/sec
• power and joules
• power and watts/sec

A circuit is shown. Which of the following is true of this circuit?

• It is series and therefore both resistors have the same voltage

• It is series and therefore both resistors have the same current

• It is parallel and therefore both resistors have the same voltage

• It is parallel and therefore both resistors have the same current

A 150-watt light bulb is brighter than a 60.-watt light bulb when both are operating at a potential difference of 110 volts. The 150-watt bulb is brighter because

• The 150watt bulb has a greater resistance
• The 60watt bulb has a greater resistance
• both have the same resistance

What must be inserted between points A and B to establish a steady electric current in the incomplete circuit represented in the diagram below?

• magnetic field source

• switch

• source of potential difference

• voltmeter

The current through a 10.-ohm resistor is 1.2 amperes. What is the potential difference across the resistor?

• 14V
• 12V
• 120V
• 8.3V

Suppose that the final connection of a wire to a battery is made for a two-bulb circuit. Which statement describes the timing by which the light bulbs light?

• The light bulb closest to the positive (+) terminal will light first.

• The light bulb closest to the negative (-) terminal will light first.

• The light bulbs light simultaneously with no apparent lighting of one before the other.