GENERAL PHYSICS 2

Capacitor stores not only charges but also energy. If there are more charges stored in the capacitor, how can it affect the potential energy in it?

• If there are more charges in the capacitor, there will be a small effect on the potential energy.

• If there are more charges in the capacitor, there will be less potential energy being stored.

• If there are more charges in the capacitor, there will be more potential energy being stored.

• If there are more charges in the capacitor, there will have no effect on the potential energy being stored in the capacitor.

Answer explanation

Always remember that charges affect the potential energy that will be generated in te capacitor.

A battery is connected to two wires of the same material but different in length. Which wire has the potential to have a greater flow of current?

• The longer wire

• The shorter wire

• Both wires will have the same current

• The current depends on the potential difference

Answer explanation

review the formula of resistance: when the value of wire is high (meaning the wire is long) the resistance will be high too, when the wire is short (low value) then the resistance will be low.

Consider also the cross sectional area of the wire wherein when it has a large value, the the resistance will be low, and when it has small value, the the resistance is high

On what factor can a capacitor store more charges?

• The plates of the capacitor should have a smaller area.

• The plates of the capacitor should have a bigger area.

• The plates of the capacitor should be closer to each other.

• The plates of the capacitor should be farther from each other.

Answer explanation

When there is a greater or bigger area, then it can store more charges compared to smaller area. (even if you relate it in a room with bigger area it can accommodate more things or people)

Distance will only make the attraction of the charges stronger.

if you combine distance and area then it can store more charges, stronger attraction, resulting to high capacitance

What material with resistance can affect the terminal voltage when the battery is not connected to the circuit?

• battery

• load and wire

• battery and load

• load, wire, and battery

Answer explanation

If battery or source is not connected in a circuit, then the terminal voltage can only be measured in its positive and negative terminal

What is the relationship between voltage and electromotive force (EMF)?

• EMF is greater than voltage

• EMF is always equal to voltage

• Voltage is always greater than EMF

• EMF is the cause of a potential difference, which results in voltage

It is said that electron flow is the real direction in which the charges or the electrons flow. How does it differ from the conventional current?

• Electron flow has the same direction of the potential difference and the electric field while the conventional current flows in the opposite direction.

• Electron flow has the direction where the electrons flow from the negative to the positive terminal while conventional current flows from positive to negative terminal.

• Electron flow has the same direction with the electric field but not with the potential difference while conventional current flows similarly with the electric field and the potential difference.

• Electron flow has the opposite direction with the electric field and but not with the potential difference while the conventional current flows similarly to the electric field and the potential difference.

Answer explanation

Same Direction
Conventional current=potential difference/voltage=electric field

Opposite Direction
Electrons - always starts from negative

What effect does a capacitor's dielectric constant have on its capacitance?

• It depends on the shape of the capacitor

• Dielectric constant has no effect on capacitance

• Higher dielectric constant results in lower capacitance

• Higher dielectric constant results in higher capacitance

Answer explanation

Always remember, dielectric material causes the capacitance to increase.

Which of the following best explains the reason why dielectric increases the capacitance of a capacitor?

• The dielectric material fills in the gap between the two plates of the capacitor.

• Charges present in the plates of the capacitor is attracted to the dielectric material.

• The molecules present in the dielectric material create polarity thus shortening some of the electric field.

• The electric field affects the potential difference present in the capacitor which decreases due to the presence of dielectric material.

Answer explanation

The dielectric material has charges, too. In that case the positive will be attracted to the opposite charge, creating polarity in the molecules. With that, there will be electric field that will be shorter than the electric field without the dielectric material. It causes for the V(potential difference) to decrease where,

C=Q/V

as voltage decreases, capacitance increases

From what point do we measure the terminal voltage?

• To the wire across the bulb

• To the positive and negative terminal of the battery

• To the positive terminal and the wire before the bulb

• To the bulb and the negative terminal of the battery

Where do we get the resistance that can affect the voltage and current in the circuit?

• From the battery only

• From the load and the wire

• From the battery and the load

• From the load, wire, and battery

Answer explanation

Same Direction
Conventional current=potential difference/voltage=electric field

Opposite Direction
Electrons - always starts from negative