Paper 1 practicals

Question 1

How to investigate the specific heat capacity of materials?

Answer 1

1) place a beaker on a balance and press zero
2) Now add the oil to the beaker and record the mass of the oil
3) Place a thermometer and an immersion heater into the oil
4) read the starting temperature of the oil
5) wrap the beaker in insulating foam to reduce thermal energy transfer to the surroundings
6) connect a joulemeter to the immersion heater and switch on for 1 minute
7) measure the end temperature and the amount of energy that passed through the immersion heater by reading the joulemeter
8) repeat using different liquids or a metal block

Question 2

specific heat capacity practical variables

Answer 2

the independent variable is the type of liquid

the dependant variable is the temperature

control variables are the amount of liquid used and energy provided

Question 3

specific heat capacity practical hazards and risks

Answer 3

the electrical heater could be very hot so you must not touch it directly

if the liquids become hot they could boil and spit, so safety goggles must be worn and the heater should not be left on for longer than necessary

Question 4

investigate the V-I Characteristics of a filament lamp, a diode and a resistor at constant temperature

Answer 4

set up the standard test circuit

use the variable resistor to adjust the potential difference across the test component

measure the voltage and current for a range of voltage values

repeat the experiment at least three times to be able to calculate a mean

repeat for other components to be tested

Question 5

variables for the investigate the V-I characteristics of a filament lamp, a diode and a resistor at constant temperature

Answer 5

the independant variable is the potential difference across the component set by the variable resistor

the dependant variable is the current through the component, measured by the ammeter

Question 6

Hazards and risks for the V-I characteristics required practical

Answer 6

the main risk is that the filament lamp will get hotter as the current increases which can cause burns.

if it overheats, the bulb will blow and must be allowed to cool down before attempting to unscrew and replace it

Question 7

considerations, mistakes and errors for the V-I characteristics required practical

Answer 7

before taking measurements, check the voltage and current with the supply turned off. this will alloq zero errors to be udentified

a common error is simply reading the supply voltage as the voltage across the component. at low component resistances, the wire will take a sizeable share of this voltage, resulting in a lower voltage across the component. this is why a voltmeter is used to measure the voltage across the component