Paper 3 Physics

Question 1

If given 10 oscillations and need to calculate percentage uncertainty of 1 oscillation how do you do it?

Answer 1

Calculate the percentage uncertainty in 10 oscillation time. This is your percentage uncertainty in you value of time for one oscillation.

0.1/ time value for 10 oscillations x100

Percentage uncertainty if unaffected by multiplying or dividing by constants. The percentage uncertainty Is always taken from the value you ACTUALLY measured or read or took.

Question 2

Why is It important to use a voltmeter with very high resistance when taking a potential difference reading across a capacitor?

Answer 2

To ensure the capacitor does not lose charge through the meter. This would affect the p.d. value taken.

Question 3

If a question asks you to calculate 2% of a specific value how many significant figures should you give the answer to?

Answer 3

As many as the percentage uncertainty. If 2%, then 1s.f.

Question 4

When showing a relationship is an inverse-square law or something else what should you do?

Answer 4

If the values are from a graph always keep them in the units of the graph.

Question 5

What is one problem with using vernier callipers?

Answer 5

Callipers could reduce the reading.

Question 6

Why does P stay at rest when inverted?

Answer 6

Pressure is reduced when cylinder is inverted.
Pressure is less than atmospheric pressure.
Creates an upward force on P.

Question 7

What should you always do with lines of best fit?

Answer 7

Try to make them as steep as possible.

Question 8

When they say “ marked in x intervals” what does this mean?

Answer 8

The smallest possible lines (just an error because I didn’t know what they meant) are those intervals.

Question 9

What should you say when the qeuestions asks why the data does’t ho that the relationship is an inverse square law?

Answer 9

There is significant difference in the values.

Question 10

Radioactive decay is?

Answer 10

Random (not spontaneous)

Question 11

Why is a peak further from the central maximum harder to read, why does it have greater uncertainty?

Answer 11

Less defined or maximum is wider

Question 12

Why is non-zero minimum produced when reflected waves superpose direct waves?

Answer 12

The waves have different energies and amplitudes because some energy is absorbed on reflection.

Question 13

What should you always do when calculating gradient?

Answer 13

Draw a gradient triangle.