CHAPTER 20: ELECTRIC CURRENT, RESISTANCE, AND OHM’S LAW (Exam 2)

What is electric current?

Rate of charge flow.

What is the current equation?

I = Q/t.

What is the unit of current?

Ampere (A) = C/s.

What is conventional current?

Flow of positive charge.

Which way do electrons move?

Opposite conventional current.

What is drift velocity?

Average velocity of free charges.

What is Ohm’s law?

V = IR.

What is resistance?

Opposition to current flow.

What is an ohmic material?

Resistance stays constant as V and I change.

What is resistivity?

Material's resistance to current.

What is the resistance equation?

R = ρL/A.

How does length affect resistance?

Longer wire → greater resistance.

How does area affect resistance?

Larger area → lower resistance.

What is electric power?

Rate of energy transfer.

What are the 3 power equations?

P = IV, P = I²R, P = V²/R.

What is the unit of power?

Watt (W).

What is DC?

Current flows in one direction.

What is AC?

Current periodically reverses direction.

What does RMS mean?

Root mean square.

What is the AC RMS voltage equation?

Vrms = Vpeak/√2.

What is frequency?

Cycles per second (Hz).

What is the frequency-period relationship?

f = 1/T.

What is a thermal hazard?

Excessive electrical heating.

What is a shock hazard?

Current passing through a person.

Why does the body conduct electricity?

It contains water.

How do insulating shoes help?

They provide high resistance.

What is a short circuit?

A very low-resistance path causing large current.

What determines shock severity?

Current, duration, and path through the body.

What is the electron charge?

−1.60 × 10⁻¹⁹ C.