Third Quarterly Assessment in Physics

Which of the following correctly shows the process of charging by rubbing?

• A balloon is rubbed against wool, and both remain neutral.

• A balloon is rubbed against wool, but no charges are transferred between them.

• A balloon is rubbed against wool, and the balloon gains positive charges while the wool gains negative charges.

• A balloon is rubbed against wool, causing the balloon to gain negative charges and the wool to gain positive charges.

What happens to electrons during the process of electrostatic charging by rubbing?

• Electrons are destroyed during the process.

• Protons are transferred from one object to another.

• Electrons are transferred from one object to another.

• Electrons and protons move together between objects.

Which of the following is the CORRECT sequence to demonstrate electrostatic charging by induction using a metal sphere and a charged rod?

• Bring a charged rod close to a metal sphere, touch the rod to the sphere, then remove the rod.

• Touch a metal sphere with your hand, bring a charged rod close, remove the rod, and then remove your hand.

• Bring a charged rod close to a metal sphere, remove the rod, touch the sphere with your hand, and then remove your hand.

• Bring a charged rod close to a metal sphere, touch the sphere with your hand, remove your hand, and then remove the rod.

A point charge q1=+3C is located at the origin, and another point charge q2=−2C is 4 meters away from q1. What is the magnitude of the force between these two charges? (Use Coulomb’s constant k=8.99×10^9 N⋅m^2/C^2)

• -3.37×10^9 N

• -3.37×10^10 N

• -3.37×10^11 N

• –3.37×10^12 N

What is the correct unit of electric flux?

• Newton (N)

• Coulomb (C)

• Volt·meter (V·m)

• Newton meter squared per coulomb (N·m²/C)

What does Gauss’s law describe about electric fields?

• It relates electric flux to the enclosed charge.

• It explains how magnetic fields create electric fields.

• It describes how electric fields are created by moving charges.

• It states that electric fields are always zero inside a conductor.

If the electric field intensity is 200 N/C and the area is 0.5 m², and the angle between the field and the area is 30°, what is the electric flux?

• 80 N·m²/C

• 87 N·m²/C

• 90 N·m²/C

• 97 N·m²/C

What is the relationship between electric potential and the work done on a charged particle?

• Electric potential is equal to the work done divided by the charge.

• Electric potential is directly proportional to the work done by the electric field.

• Electric potential is inversely proportional to the work done by the electric field.

• Work done on a charged particle is always zero when moving in a constant electric field.

What determines the electric potential at a point in space?

• The amount of electric current passing through that point.

• The work done per unit charge to bring a positive test charge from infinity.

• The amount of electric charge at that point and its surrounding electric field.

• The speed of a charged particle moving through the electric field at that point.

Which of the following BEST defines an electric field?

• A space where only neutral particles interact.

• The area where a magnetic field affects a moving charge.

• A region around a charged particle where it exerts force on other charges.

• A region around a charged particle where its mass is felt by other objects.