Electricity and Circuits Concepts

A balloon was rubbed on a wool sock and the balloon was placed against the wall and it stuck. What causes this?

• Static Electricity

• Gravity

• Magnetism

• Electric Current

Answer explanation

The balloon becomes charged with static electricity when rubbed on the wool sock. This charge allows it to attract and stick to the wall, demonstrating the effects of static electricity.

Tags

NGSS.MS-PS2-3

An electric motor converts _____________ into ______________.

• Electromagnetic energy;thermal energy

• electrical energy;electromagnetic energy

• mechanical energy;electrical energy

• electrical energy;mechanical energy

Answer explanation

An electric motor converts electrical energy into mechanical energy, enabling it to perform work, such as turning a fan or driving a pump. This is the fundamental operation of electric motors.

Tags

NGSS.HS-PS3-3

A generator converts __________________ into _____________________,

• electrical energy;mechanical energy

• mechanical energy;electrical energy

• thermal energy;electromagnetic energy

• electromagnetic energy;chemical

Answer explanation

A generator converts mechanical energy into electrical energy. This process involves using mechanical motion to generate electricity, making the correct choice 'mechanical energy; electrical energy'.

Tags

NGSS.HS-PS3-3

An open circuit means:

• a switch is off and electrical energy will not flow

• a switch is off and electrical energy will flow

• a switch is on and electrical energy will not flow

• a switch is on and electrical energy will flow

Answer explanation

An open circuit occurs when a switch is off, preventing electrical energy from flowing. Therefore, the correct choice is that a switch is off and electrical energy will not flow.

A closed circuit means

• a switch if off and electrical energy will not flow

• a switch is off and electrical energy will flow

• a switch is on and electricity will flow

• a switch is on and electricity will not flow

Answer explanation

A closed circuit occurs when a switch is on, allowing electrical energy to flow freely. This is essential for powering devices, making 'a switch is on and electricity will flow' the correct choice.

After running a comb through his hair Fred noticed when he went to wash it this happened. What could cause this?

• Running the comb through his hair made it more absorbent

• The comb had become electrically charged

• The comb had become warmer

• Some of the chemical bonds in the comb and become broken

Answer explanation

When Fred ran the comb through his hair, it likely became electrically charged due to friction. This static charge can cause hair to stand up or clump together, which is a common phenomenon when using plastic combs.

Tags

NGSS.MS-PS2-3

Which of the following is a good insulator

• rubber

• gold

• copper

• aluminum foil

Answer explanation

Rubber is a good insulator because it does not conduct electricity well, making it ideal for preventing electrical flow. In contrast, gold, copper, and aluminum foil are excellent conductors of electricity.

Tags

NGSS.MS-PS3-3

Which of the following is a good conductor?

• rubber

• plastic

• copper

• glass

Answer explanation

Copper is a good conductor of electricity due to its high electrical conductivity, making it ideal for electrical wiring. In contrast, rubber, plastic, and glass are insulators and do not conduct electricity well.

Tags

NGSS.MS-PS2-5

LED or light emitting diodes allow electricity to flow in only one direction. What type of material is the LED?

• conductor

• insulator

• semiconductor

• capacitor

Answer explanation

LEDs are made from semiconductor materials, which allow them to conduct electricity in one direction. This property is essential for their function in electronic devices, distinguishing them from conductors and insulators.

Tags

NGSS.MS-PS2-3

As you add more bulbs to a series circuit, the amount of current in the wire:

• decreases

• increases

• stays constant

• will move back and forth

Answer explanation

In a series circuit, adding more bulbs increases the total resistance. According to Ohm's law, as resistance increases, the current decreases. Therefore, the amount of current in the wire decreases as more bulbs are added.