Module 4 - Circuits & Current

Electric Fields of Dreams

5

Draw the electric field lines for a positive and negative charge. 

Field lines go outward from a positive charge and inward for a negative one. 

10

Are wires ever empty of charge? Why?

No, because even without a flow of current, wires still possess electrons. 

15

If there are 2 charges, and the distance between them is doubled, what is the change in the magnitude of the force?

Reduced by 1/4

20

If you were on a walk using a compass to find your way through the city and every so often the compass needle deflected, what would be going on?

Presence of moving currents deflecting the magnetic field.

Put a Feather in Your Cap-acitor

5

What is the function of a capacitor in a circuit?

To store electrical energy until needed later. 

10

How are capacitors constructed?

2 parallel conducting plates with an insulator (dielectric) in the middle.

15

Describe one difference between a capacitor and a battery.

1. Discharge speed

2. Storage of charge

3. Construction

20

How can I increase the capacitance of a capacitor?

The area of the plates

 The distance the plates are separated

 The material that is placed between the plates

I Like The Circuit of Your Jib

5

Identify the circled components in this image. 

10

Which direction do the electrons flow in this circuit?

From the negative terminal to the positive.

15

A hair dryer draws 5.0 A when plugged into a 60 V line. What is the resistance within the hair dryer?

V=IR

R=V/I=(60V)/(5.0 A)

R=12 Omega

20

Which of these 2 circuits has the highest total resistance?

The circuit on the left, because parallel resistors are the sum of the reciprocals of the resistor values.