Resistance and Ohm's Law

Question 1

What is electrical resistance?

Answer 1

Electrical resistance is a measure of how difficult it is for electrons to flow through part of a circuit

Question 2

What are the three things that can affect resistance?

Answer 2

Length, Width, Material

Question 3

What does the resistance to the flow limit?

Answer 3

The electric current

Question 4

How much resistance do conductors have?

Answer 4

Conductors have very little resistance, They allow large electric currents to flow with little loss of energy

Question 5

How much resistance do insulators have?

Answer 5

INsulators have very large electrical resistance, They allow very little electric current to flow

Question 6

What letter is used to represent resistance?

Answer 6

The letter R is used to represent resistance and its unit is the ohm (Ω)

Question 7

WHat are materials called if they obey Ohm’s law?

Answer 7

ohmic

Question 8

How do you find if a material is ohmic?

Answer 8

It is possible to find out if a material is ohmic by drawing a graph of voltage drop vs electric current

-If the material is ohmic resistance (R) is constant

-The graph of Voltage (V) vs Current (I) will give a straight line

-The gradient of the line is equal to the resistance

Question 9

What are resistors used to do?

Answer 9

Resistors are used in electric circuits to control voltage and current

-They can have a fixed resistance or can be variable

Question 10

What does increased resistance cause?

Answer 10

Increased resistance causes a decrease in the amount of current flowing through the circuit