PHYS SCI B Unit 5 Review

In models of magnetic and electric fields, why are field vectors depicted by arrows?

• because they represent their magnitude, but not their direction

• because they represent both their magnitude and direction

• because they represent a parameter that is neither their magnitude nor direction

• because they represent their direction, but not their magnitude

A model depicts two balloons of the same size with identical negative charges being moved toward one another at the same speed. How will the balloons interact with each other?

• They will attract, moving in the same direction at the same speed.

• They will repel, moving in opposite directions at the same speed.

• They will attract, moving in opposite directions at different speeds.

• They will repel, moving in the same direction at different speeds.

A model shows a machine that works using electrical fields. What would this machine need for the electrical field to function properly?

• at least two charged, interacting parts

• springs, to store potential energy

• all neutral components

• moving parts, for kinetic energy

During chemical reactions, bonds between atoms break and form. What does this mean in terms of subatomic particles?

• Electrical fields of charged particles interact, bonding those with opposite charges.

• Electrical fields of charged particles interact, bonding those with the same charge.

• Electrical fields of neutral particles interact, bonding those with the same charge.

• Electrical fields of neutral particles interact, bonding those with opposite charges.

What is the driving force behind chemical reactions between elements?

• the attraction of electrons of different atoms

• the interaction of the electric fields of neutrons and electrons

• the interaction of the electric fields of protons and electrons

• the attraction of protons of different atomschchemical reacrion

A community seeks to develop a maglev train operation. Which of the following is most likely their technical motivation for choosing this option?

• They hope to employ lighter weight materials that reduce costs.

• They need trains that can cover particularly long distances.

• They seek a rail line not affected by friction.

• They do not want to rely on any supply of electricity.

A student places two horseshoe magnets next to each other, and the poles of the magnets attach to each other. How does the kinetic energy of the system change?

• Kinetic energy decreases because the magnets move in the opposite direction of the field. 

• Kinetic energy increases because the magnets move in the direction of the field. 

• Kinetic energy increases because the magnets move in the opposite direction of the field. 

• Kinetic energy decreases because the magnets move in the direction of the field. 

The image shows a simple electromagnet that does not attract metal objects.

Why is the electromagnet not attracting the metal nails?

• The wire was not connected to the source.

• The metallic objects lost their magnetic domains.

• The model needs a switch in order to work.

• The battery was replaced with a lower voltage.

What is the strong nuclear force?

• a force that acts on charged particles

• a force that is responsible for certain elements breaking down

• a force that attracts objects with mass towards each other

• a force that holds atomic nuclei together

On which planet is gravity strongest?

• Jupiter

• Mars

• Earth

• Mercury