Physics U6 Flashcards
(22 cards)
Data Logger:
More reading taken in a given long time,
High sampling rate.
Less uncertainty of variables.
Measurement of 2 variables simultaneously.
Used remotely.
Property of A.U. and %U:
AU, Same d.p. With mean,
%U 2 s.f.
Digital Camera:
View oscillation in slow motion, minimum found more accurately.
Judge if oscillation stops, xx stops moving.
Oscillation T period measurement:
Use small initial displacement.
Use timing marker directly below specific part of x when undisplaced from eqm centre of oscillation
Starting timing after serval oscillation settles,
Measure time of multiple numbers of oscillations divided by number of oscillations.
Repeat measurement of T to calculate mean T.
6 marker:
Control
Procedure
Technique + errors
Turn on the tap (x) and start timing (y)
Record y and corresponding, successive at least many 5 values/measurements
Repeat measure of x to calculate mean.
Plot graph check if straight line.
Resolution of apparatus:
Meter rule 1mm
Vernier 0.1mm
Micrometer 0.01mm
Measurement micrometer/vernier
Measure length of different orientation and location, reduce effect of random error.
Check and correct zero error, eliminate systematic error.
Safety of coil:
Risk of overheating, hot, short circuit > low p.d. Add resistor to circuit.
Risk of electrical shock > low p.d. Use insulator gloves.
Safety of Capacitor:
Capacitor should connected with correct polarity,
Don’t exceed the working pd of the capacitor.
Ensure capacitor fully discharged when handling after experiment.
Safety of hot water:
Risk of burn of hot beaker,
handle beaker with insulating gloves or tongs
Comment on relationships of graph:
Not enough sets of data,
Range of data too small
Origin no pass
Accurate bfl not drawn
Why rubber band not accurate:
Length of x doesn’t take into account folded parts.
Rubber band measured when not taut/compressed.
Why peak not accurate:
Not enough data around the maximum.
bfl / peak uncertain
Why variable resistor used:
Ensure pd across the diode is constant.
Temperature will affect the resistance of the diode.
How to measure the value of time period from pulses?
Measure number of division between same points of pulses (Peak)
Multiply by number of division by time per division
Measure first and last pulse divide by 2.
Systematic error/ zero error explanation:
May add constant value to measurements
Light gate:
Eliminate reaction time
Reduce parallax error.
Light gate is in a fixed position.
Safety of radiation:
Handle the source with long tongs.
Maintain safe and long distance from source when used.
Keep in lead lined box when unused.
Use the source as short a time as possible.
Capacitor 6 marker:
Charge capacitor to initial pd
Ensure ammeter and stopwatch close together
Start stopwatch when changing switch.
Record current at successive intervals in times.
Take many at least 5 repeat.
Horizontal:
Use spirit level check if bubble is central
GM 6 marker:
Procedure
Ensure source detector in line with same distance:
BG count rate,
Count
Corrected= count - bg
D metre rule
Repeat D
Plot graph
Justify suggestion T = kl^n:
Log
y=mx + c
Non zero y int
K not equal to one. correct
