Exploring Electric and Magnetic Forces

Which of the following best describes the relationship between electric charges and magnetic fields?

• Electric charges create magnetic fields only when they are stationary.

• Electric charges create magnetic fields when they are in motion.

• Magnetic fields create electric charges.

• Electric charges and magnetic fields are unrelated.

What happens to the force between two electric charges if the distance between them is doubled?

• The force is doubled.

• The force is halved.

• The force is quadrupled.

• The force is reduced to one-fourth.

Which of the following materials is most likely to be a good conductor of electricity?

• Rubber

• Glass

• Copper

• Wood

If a magnetic field is applied perpendicular to the direction of an electric current, what is the resulting effect called?

• Electric induction

• Magnetic resonance

• Electromagnetic interference

• Lorentz force

Which of the following devices uses the principle of electromagnetic induction?

• Battery

• Transformer

• Resistor

• Capacitor

What is the unit of electric current?

• Volt

• Ohm

• Ampere

• Watt

Which of the following statements is true about magnetic poles?

• Like poles attract each other.

• Opposite poles repel each other.

• Like poles repel each other.

• Magnetic poles do not interact.

What is the effect of increasing the number of coils in an electromagnet?

• The magnetic field strength decreases.

• The magnetic field strength increases.

• The magnetic field direction changes.

• The electromagnet stops working.

Which of the following is a correct statement about electric fields?

• Electric fields are created only by moving charges.

• Electric fields can exist in a vacuum.

• Electric fields are always visible.

• Electric fields cannot exert force on charges.

What is the primary function of a capacitor in an electric circuit?

• To increase current

• To store electrical energy

• To convert AC to DC

• To decrease voltage