Electromagnetism and Static

A __________________ is a current-carrying coil of wire with many loops

• magnet
• solenoid
• electromagnet
• compass

A positively charged balloon is brought near a negatively charged balloon. Which statement best describes what happens?

• The balloons will be attracted to each other.
• The balloons will be repelled by each other.
• The positive balloon will not react, the negative balloon will move towards the positive.
• The negative balloon will not react, the positive balloon will move away from the negative.

An object has 25 negative charges and 36 positive charges. What is the object's overall charge?

• Cannot be determined without knowing the neutrons.
• Negative
• Positive
• Neutral

For which types of forces are the following statement true: Like repels like. SELECT TWO ANSWERS.

• Magnetic
• Friction
• Electric
• Gravitational

A balloon is rubbed against wool, which statement correctly identifies the charge of the wool and how it gained that charge after the balloon is rubbed against it.

• The wool is positive because it took protons from the balloon.
• The wool is positive because it lost electrons to the balloon.
• The wool is negative because it took electrons from the balloon.
• The wool is negative because it lost protons to the balloon.

Moving ________ create a magnetic field.

• wires
• photons
• electrons/charges
• batteries

What conclusion can you draw from this graph?

• As current increases, magnetic strength decreases
• As current increases, magnetic strength increases
• As current decreases, magnetic strength increases
• There is no relationship between current and magnetic strength

Which of the following would be the best core of an electromagnet?

• pencil
• iron nail
• plastic spoon
• aluminum rod

What does this represent?

• electromagnet
• permanent magnet
• solenoid
• battery

Consider three electromagnets. Both have 6 A of current running through the wires. Magnet A has 20 coils/turns of the wire along the iron core. Magnet B has 10 coils/turns of the wire along the iron core. Magnet C has 30 coils/turns of the wire along the iron core. Which statement best explains which is the strongest and why?

• All the magnets have the same strength because they have the same current.
• Magnet A is strongest because it has the average number of coils.
• Magnet B is the strongest because it has the least number of coils.
• Magnet C is the strongest because it has the greatest number of coils.