Physics Unit 2 Electricity Chp 3 Electrical resistance

What is the function of a resistor?

Controls the amount of current flowing around the circuit.

What are 2 types of resistors?

Fixed resistor and variable resistor (Rheostat)

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What is the resistor reading equation?

R = AB x 10^C

OBJR

What is Ohm’s Law and equations like to it?

If the conductor is kept at a constant temperature, the current flowing through it is directly proportional to the potential difference between its ends. 

I is directly proportional to V 

I = 1/R x V 

V = IR

R = V/I 

1/R = I/V

V=voltage, I=current, R=resistance

How can we say I is directly proportional to V from the graph?

The graph is a straight line and passes through the origin.

What is the relation between the gradient of the graph and the resistor relation?

Steeper gradient→smaller resistance

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Relation and equation of resistor, length of conductors, cross-sectional area of conductor

R is directly proportional to L/A

R = ρL/A

ρ=resistivity, L=length of conductor, A=cross-sectional area of conductor, R=resistance

How does resistance result in “same length, different cross-sectional area wire” and “same cross-sectional area and different length wire”

In same length and different cross-sectional area, the larger the cross-sectional area→smaller the resistance 

In the same cross-sectional area and different lengths, the longer the length of wire→greater the resistance.