E.M.F And Internal Resistance

Question 1

[………] have an Internal Resistance.

Answer 1

Batteries

Question 2

Resistance in metals comes from electrons colliding with 1-[………] and 2-[………] energy

Answer 2

1-Atoms (or ions)

2-losing

Question 3

In a battery what kind of energy does it use to make electrons move?

Answer 3

Chemical energy

Question 4

What is Internal Resistance?

Answer 4

Is when electrons collide with atoms inside the battery creating a resistance

Question 5

Internal resistance is what makes batteries and cells [……..][….] when they are used.

Answer 5

Warm up

Question 6

We assume wires have […….] resistance.

Answer 6

Zero

Question 7

What is Load resistance?

Answer 7

Is the total resistance of all the components in the external circuit, can also be called ‘external resistance’

Question 8

How does a battery produce energy?

Answer 8

By chemical reactions

Question 9

What is the Electromotive force or E.M.F?

Answer 9

The total amount of work the battery does on each coulomb of charge.

Question 10

What is E.M.F measured in?

Answer 10

Volts

Question 11

What is the E.M.F equation?

Answer 11

ε = W / Q

Question 12

ε = W / Q What is W?

Answer 12

Is the work done on the charge.

Question 13

What is the Potential Difference across the load resistance?

Answer 13

Is the work done when one coulomb of charge flows through the load resistance. Is called the ‘terminal P.D’

Question 14

What would the the Terminal P.D equal if there was no internal resistance?

Answer 14

Terminal P.D would be the same as the E.M.F

Question 15

What is the energy that is waged by overcoming the internal resistance called?

Answer 15

Lost Volts

Question 16

What is Lost Volts?

Answer 16

The energy water per coulomb overcoming the internal resistance

Question 17

How does the conservation of energy law apply to Internal Resistance?

Answer 17

Energy per coulomb supplied by the source = energy per coulomb used in load resistance + energy per coulomb wasted in internal resistance

Question 18

List 4 different E.M.F equations.

Answer 18

ε = V + v
ε = I(R + r)
V = ε - v
ε = V + Ir

Question 19

What does ε stand for?

Answer 19

E.M.F

Question 20

What does V stand for?

Answer 20

Terminal P.D ( the p.d across the load resistance)

Question 21

What does v ( little v ) stand for?

Answer 21

Lost volts

Question 22

What does I stand for?

Answer 22

Current

Question 23

What does R stand for?

Answer 23

Load resistance

Question 24

What does r stand for?

Answer 24

Internal resistance ( resistance inside the battery )

Question 25

How do you calculate E.M.F (ε) for multiple cells in series?

Answer 25

ε(Total) = ε(1) + ε(2) + ε(3) | Add their individual E.M.Fs together

Question 26

How do you calculate the E.M.F for multiple IDENTICAL cells in Parallel?

Answer 26

ε(Total) = ε(1) = ε(2) = ε(3) | The total E.M.F of the combination of cells is the same size as the E.M.F of each of he individual cells

Question 27

What is the independent variable?

Answer 27

The variable you change

Question 28

What is the dependant variable?

Answer 28

Is the variable you measure

Question 29

What is the control variable?

Answer 29

Is the variable you do not change

Question 30

When investigating Internal Resistance and E.M.F what do we measure?

Answer 30

The P.D for servers different values of current | - Bart the current by changing the value of the load resistance with the variable resistor

Question 31

When investigating Internal Resistance, what kind of graph do we plot?

Answer 31

P.D (y axis) | Current (x axis)

Question 32

When measuring Internal Resistance and E.M.F what equation do we rearrange?

Answer 32

ε = V + Ir

Question 33

When investigating Internal Resistance and E.M.F - what do we rearrange ε = V + Ir to give?

Answer 33

V = -rI + ε

Question 34

When investigating Internal Resistance and E.M.F, what part of V = -rI + ε are constants?

Answer 34

ε & r

Question 35

When investigating the Internal Resistance and E.M.F, what does the y-intercept equal on a P.D (y axis) to Current (x axis)?

Answer 35

Y-intercept = ε

Question 36

When investigating Internal Resistance and E.M.F, what does the gradient on a P.D (y axis) to Current (x axis) equal?

Answer 36

Gradient = -r