Better Practicals

Question 1

Specific heat capacity

Answer 1

Place a beaker on a balance and press zero
2. Add the substance to the beaker and record the mass of the substance.
3. Take the beaker of the balance and add an immersion heater and a thermometer into the substance.
4. Read the starting temperature of the substance.
5. Wrap the beaker in insulating foam to reduce thermal energy transfer to the surroundings.
6. Connect a joulemeter and a power pack to the immersion heat.
7 Time for 30 minutes
8. Read the total number of joules of energy that passed into the immersion
heater off of the joulemeter.
9. Read the final temperature of the substance.
10 Calculate the specific heat capacity.

Question 2

Sources of inaccuracy for specific heat capacity practical

Answer 2

Thermal energy passing out of the beaker into the air
We can reduce this by using an insulator with a lower thermal conductivity.
Not all of the thermal energy passing into the oil.
We can prevent this by ensuring that the immersion heater is fully submerged.
Incorrect reading of thermometer.
To stop this. we can use an electric temperature probe.
Thermal energy not being spread through the substance.
To prevent this. stir the substance.

Question 3

Thermal insulator changing the insulator

Answer 3

Place a small beaker inside a larger beaker
2. Use a kettle to boil some water. Then transfer 80cm3 of the water into the small beaker.
3. Use a piece of cardboard as a lid for the large beaker The lid must have a hole for a thermometer.
4 Place a thermometer through the whole in the cardboard lid Record the starting temperature of the water and start the stopwatch
5. Record the temperature of the water every 3 minutes for 15 minutes.
6. Repeat the experiment using the same volume of hot water. but use an insulating material which will fill the gap between the two beakers. Use numerous insulating materials.
7
Ensure the mass of the insulating materials is the same in each case.
8. Ensure the starting temperature is the same for each experiment.
9. Record all of the results in a table and plot a graph.

Question 4

Thermal insulator changing the thickness of insulator

Answer 4

1. Fill a beaker with 80cm3 of hot water.
2. Like method 1, record the temperature every 3 minutes for 15 minutes.
3. Repeat the experiment but wrap two layers of insulator (le newspaper) around the beaker
4. Repeat the experiment two more times using four layers and then six layers
5. Ensure starting temperature is the same for each experiment.
6. Record data in a table and then plot a graph

Question 5

Resistance p

Answer 5

1. Set up the circuit above. Attach a length or wire along a meter ruler using pieces of tape. Attach a crocodile clip at 0cm.
2. Attach the second crocodile clip at 0 cm and record the current on the ammeter and the potential difference on the voltmeter.
3. Repeat by moving the crocodile clip 10cm along the wire and each time recording the current and potential difference measured
   4 Calculate the resistance of at each point using V-IR.
4. Plot a graph.

Question 6

Iv charector IST is

Answer 6

Set up the circuit shown above.
2. Use the voltmeter to read the potential difference across the resistor.
3. Use the ammeter to read the current through the resistor.
4. Record these values in a table.
5. Adjust the variable resistor and record the new readings on the voltmeter and ammeter
6 Do this several times
7
Switch the direction of the battery. Should now get negative values.
8. Continue to take several readings.
9. Plot a graph.
10. Repeat with a lamp and diode.

Question 7

Density

Answer 7

Method (regular objects)
1. Measure the mass of the object using a balance.
2. To work out the volume of the object, use a ruler to measure the length. width and height, and multiple them all together.
3. Calculate density.

Method (irregular objects)
1. Measure the mass of the object using a balance.
2. Fill a ureka can with water to the spout.
3. Place the object in the water and collect the displaced water in a measuring cylinder.
4. Calculate density.