13.2 More about resistance

Question 1

Resistors in series pass the…

Answer 1

…same current

Question 2

The total pd of resistors in series is equal to the…

Answer 2

…sum of the individual pds

Question 3

Total resistance of resistors in series is equal to the sum of the individual resistances:

Answer 3

R = R1+R2+R3+….

Question 4

Resistors in parallel have the…

Answer 4

…same pd

Question 5

The current through a parallel combination of resistors is equal to…

Answer 5

…the sum of the individual currents

Question 6

Total resistance of resistors in parallel can be found using:

Answer 6

1/R = 1/R1+1/R2+1/R3+….

Question 7

What is the heating effect of an electric current in any component due to

Answer 7

The resistance of the component
The charge carriers repeatedly collide with the positive ions of the conducting material
There is a net transfer of energy from the charge carriers to the positive ions as a result of these collisions
After a charge carrier loses kinetic energy in such a collision, the force due to the pd across the material accelerates it until it collides with another positive ion

Question 8

If the component is at constant temperature heat transfer to the surroundings takes place at the same rate, therefore, the rate of heat transfer =

Answer 8

I^2R

Question 9

If the component heats up, its temperature rise depends on…

Answer 9

…the power supplied to it I^2R, and the rate of heat transfer to the surroundings

Question 10

The energy transferred to the object by the electric current in time t =

Answer 10

power x time = I^2R

Question 11

The energy transfer per second to the component does not depend on…

Answer 11

…the direction of the current

Question 12

How can the power of a resistor be calculated

Answer 12

P=V^2/R