For those resitting AS EMPA

Here are some practice questions, to complete, we will go through these on Tuesday 2pm in the library (come at 2.30 if you have a period 5 lesson) ready for the exam the next day in the morning 830 am.
Ms H

AS EMPA practice questions

Results from Task 2

V1 /V	V2 /V	V3 /V	V3 /V	V3 /V	V3  /V average
4.03	2.00	3.73	3.71	3.72	3.73
3.50	1.76	3.28	3.26	3.30	3.28
3.01	1.52	2.82	2.82	2.82	2.82
2.50	1.26	2.36	2.35	2.35	2.35
1.99	1.32	1.87	1.87	1.87	1.87
1.50	1.00	1.42	1.42	1.42	1.42
1.00	0.66	0.94	0.94	0.94	0.94

Questions

1. For the largest  value of V₁ what is the range of V₃ ?
2. For the largest  value of V₁ what is the percentage uncertainty of V₃ ?
3. For the smallest value of V₁ what is the percentage uncertainty of V₃ ?
4. For the smallest value of V₁ what is the uncertainty of V₁ ?
5. For the smallest value of V₁ what is the percentage uncertainty of V₁ ?
6. Draw a graph of your results on the grid provided
7. Does your line of best fit go through the origin?  Why/ Why not?
8. Were your results accurate?  Why/ why not?
9. What do you think was in the concealed unit?  Why?
10. Draw the circuit for each part of the experiment you did – what were you connecting?
11. How does potential difference split between components in series? In parallel?
12. If given the value of two of the resistors in the network, how could you use your graph to find the third?
13. What is the gradient of the graph of the above results?
14. What does this gradient represent?
15. If R2 = 1 kilo ohm, what is R3?  Use your graph to work this out.

For the above calculation, what is the percentage uncertainty for R3?  Show your working