REQUIRED PRACTICALS PAPER 1

Question 1

Investigating the specific heat capacity of different metal

Answer 1

• Place the immersion heater into the central hole at the top of the block.
• Place the thermometer into the smaller hole
• Measure and record the mass of the copper block in kg.
• Fully insulate the block by wrapping it loosely with cotton wool.
• Record the initial temperature of the block.
• Connect the ammeter, power pack and heater in series.
• Connect the voltmeter across the heater.
• Leave the heater on for a fixed amount of tiem - around half an hour
• Record the ammeter and voltmeter readings. These shouldn’t change during the experiment.
• Record the final temperature of the oil using a thermometer

Question 2

give two sources of error and how to fix them for the SPHC practical

Answer 2

1. the sources of inaccuracy and how to fix them
   - thermal energy passing out of the beaker into the air
   - use an insulator with a lower thermal conductivity
2. incorrect reading of thermometer
   use an electronic temperature probe

Question 3

thermal insulation practical

Answer 3

IV: type of insulating materials
CV : volume of hot water , same mass of insulating material in each case
DV: temperature change
- Place a small beaker into a large beaker
- use a kettle to boil water
- transfer 80cm3 of the hot water into the small bekaer
- use a piece of cardboard as a lid for the large beaker with a hole for the thermometer
- the bulb of the thermometer must be in hot water
record the intial temerature of thw ater and start a stowatch
- record the temperature of the water every three monutes for 15 minutes
- repeat the experiment using the same volume of hot water
- use an insulating material to fill ga between too beakers
- use the same method stated for different insulating materials

Question 4

investigating the factors affecting the resistance of electrical circuits

Answer 4

1. set up a simple circuit, as shown in diagram. Attach a length of wire along a metre ruler using pieces of tape. Attach a crocodile clip to one end ( at 0cm) and the second crocodile clip at 10cm on the ruler
2. Record both the current and voltage through the wire on a table
3. Repeat by moving the crocodile clip 10cm along the wire and each time recording the current and voltage measured
4. Calculate the resistance of the wire at each point using the equation V=IR
5. Plot a graph of length of wire against resistance

Question 5

Give two ways to prevent heating effect of the wire in RP3

Answer 5

• use a low pd which keeps current low reducing any heating
• only turn on current when taking a reading

Question 6

Investigating the current/voltage characteristics of circuit/components

Answer 6

1. Construct the circuit shown in the diagram below.
2. Set the variable power supply or variable resistor to the lowest setting for potential difference.
3. Record the current and voltage over the resistor.
4. Increase the current from the power supply by 2V and repeat your readings.
5. Change the resistor to a filament lamp and repeat the experiment.
6. Change the filament to a diode and protective resistor (to restrict high currents flowing through the diode), ensuring the diode is the correct direction to allow the flow of current through. Change the ammeter to a milliammeter, since the current measured will be smaller than for the other components.
7. Plot a graph of current against potential difference foreachcomponent.