Electricity & Magnetism

Question 1

What is drift velocity?

Answer 1

Average velocity that a particle, such as an electron, attains due to an electric field

Question 2

What is the difference between resistance and resistivity?

Answer 2

Resistivity is intrinsic of the material.

Resistance depends on the shape, length, and resistivity of a material

Question 3

On a voltage source, which line is higher potential in the electric circuit diagram?

Answer 3

The longer line is the positive terminal and the higher potential. The shorter line is the negative terminal and the lower potential.

Question 4

By convention, which way does a current go?

Answer 4

It goes the direction that a positive charge would flow even though the actual charge moving may be a negative charge

Question 5

What is the formula for the rate at which heat energy is dissipated?

Answer 5

This is basically power dissipated by resistor, so the formula is P = I^2 * R

Question 6

What is the power supplied to a circuit by a voltage source? Formula?

Answer 6

P = I*V

Question 7

Don’t forget how to find energy or work from power!

Answer 7

Work = Energy = Power/time