IPC Electricity Review

In an experiment, students took new identical batteries and tested their life when powering 1 bulb, 2 bulbs in series, and 2 bulbs in parallel. The table below gives the effective battery life for each circumstance.

Which statement seems reasonable from the above findings?

• Batteries are designed for series circuits.

• Batteries always last longer with 2 bulbs

• Bulbs in series draw less current from a battery.

• Bulbs in parallel have more resistance than bulbs in series.

A hair dryer has a resistance of 8.50 ohms, and 110 volts is supplied by the electrical outlet. What amount of current is flowing? (Give the answer in amps, using two decimal places.)

• 12.94 A

• .077 A

• 935 A

• None of the above

A 6.2 volt battery sends a 0.44 amp current through a miniature light bulb. Calculate the resistance for the light bulb. (Give the answer in ohms, using two decimal places.)

• .071 Ohms

• 2.73 Ohms

• 14.09 Ohms

• None of the above

When a piece of glass is inserted into a simple circuit, the light bulb of the circuit does not light up. Under these conditions, this would mean the glass is a(n) —

• resistor

• conductor

• insulator

• capacitor

An open circuit —

• allows electricity to flow

• has no resistance

• requires little voltage

• does not allow electricity to flow

A student is using a simple circuit of wires, a battery, and a small light bulb to test objects for electrical conductivity. How would the student know which object is the best conductor?

• The object which allows the bulb to glow the brightest is the best conductor

• The object which allows the bulb to no glow is the best conductor

A student is working with two electrical devices. Device A uses a current of 6.0 amps and has a resistance of 4.5 ohms. Device B uses a current of 8.0 amps and has resistance of 3.5 ohms.

Which device uses the least amount of voltage?

Provide evidence to support your answer?

• Device A: 27 V

  Device B: 28 Device A uses the least voltage

• Device A: 1.3 V

  Device B: 2.3 V

  Device A uses the least voltage

• Device A: 0.75 V

  Device B: 0.44 V

  Device B uses the least voltage

• None of the answers are correct

A student experimented by placing a second bulb and then a third bulb in series with an existing battery and bulb. The student noticed that as each bulb was added, all bulbs got dimmer. As an experimental control, all of the bulbs in the circuit were identical.

Which statement represents a valid conclusion from the above experiment?

• The electrons get tired as they go through each bulb and are really tired when they get to the third bulb.

• Three bulbs draw more current from the battery, pulling its voltage down.

• The first bulb uses up some of the current, leaving less for the other bulbs.

• The resistance of three bulbs in series is greater than the resistance of one bulb.

The diagram below represents a circuit. How much current is flowing through the circuit?

• 0.55 A

• 1.81 A

• 8.0 A

• 14.5 A

The values shown in the table below are a measure of how much current will flow in a standard sample of metal when the sample is attached to a voltage source. Which metal is the best conductor of electricity?

• Aluminum

• Copper

• Iron

• Silver