Presentation on theme: "Ohm’s Law. Measuring Current Current is measured in units of amperes (A) In a series circuit, current is the same at all the points In a parallel circuit,"— Presentation transcript:
Measuring Resistance Resistance – slows down current, adding components to a circuit increases resistance Resistance is measured in units of ohms (Ω) More resistance = Less current = Less light In a series circuit, add up all resistance to get total.
How much voltage gives 5 amps of current through a 3 Ω light bulb? I = V/R V = (5A) (3Ω) V = 15V
How much current flows in a circuit with a 1.5 volt battery and three 1 ohm resistances (bulbs) in series? I = V/R I = (1.5V) / (3Ω) I =.5A
What is the voltage drop across each resistor in the circuit? 9V/3 = 3V In a series circuit, voltage is shared between all the points
A light bulb with a resistance of 1.5Ω is connected to a 1.5V battery in the circuit. Calculate the power used by the light bulb? P = IVI = V/R I = (1.5V) (1.5Ω) I = 2.25A P = (2.25A) (1.5V) P = 3.375 W