PERA 2nd Semester 'Post-Test' Preparation

How would a NEUTRALLY charged object become POSITIVELY charged in a class activity?

• Add a proton

• Add an electron

• Remove an electron

• Remove a proton

The electrical force between two objects is 16N. What is the new force if we double the distance between the objects without changing the charges of either object?

• 4 Newtons

• 8 Newtons

• 16 Newtons

• 64 Newtons

The SI (International System) Unit for CHARGE is...

• Amp (Amperage)

• Coulomb

• Volt

• Ohm

The diagram below that best represents the charge distribution on a neutral electroscope when a negatively charged rod is held near it is:

• A

• B

• C

• D

The electric field around two positive charges looks most like:

(*HINT: electric field lines ALWAYS show arrows pointing AWAY from the positive charge and toward the negative charge)

• A

• B

• C

• D

Electrostatics and Coulomb's Law: The force between two charges is 5 newtons. What happened to the distance between the two charges if the force between them increased to 20 newtons?

• The distance between the two charges is increased to 4 times the original.

• The distance between the two charges is cut to by 1⁄4 of the original.

• The distance between the two charges is increased to twice the original.

• The distance between the two charges is cut to HALF of the original.

Answer explanation

By HALVING the distance between charged objects, we've INCREASED the electric force by 4x's, due to the inverse square law.

The wiring in your home uses ____ circuits.

• Parallel circuits

• Series circuits

• Two-way circuits

• Three-way circuits

8. This graph shows the current through a resistor as the voltage is changed. The resistance of the bulb is ___ ohms.

*HINT: Interpret the graph so that you can see the Current (I) divided by Voltage (V) = Resistance...so 2/3 = 0.67 ohms.

• 6 ohms

• 0.67 ohms

• 5 ohms

• 1.5 ohms

The motion of charges in wires, motors, light bulbs and other devices is best called electric:

• Power

• Voltage

• Current

• Conductance

In an electrical circuit, a voltage difference...

• Supplies energy to make current flow

• Causes a short circuit

• Is the term used for rate of charge flow

• Wastes energy