Practicals

Question 1

What are the key points for the practical:

Determining internal resistance

Answer 1

• Circuit including ammeter, cell, variable resistor, voltmeter
• Measure I and V for multiple resistances repeating as you go
• Plot graph of V/I
• Gradient wil be equal to r (from ε=V+Ir)

Question 2

What are the key points for the practical:

Determining the relationship between terminal velocity and radius of a sphere

Answer 2

• Measure the diameter using vernier calipers and average
• Set up long tube filled with liquid and a ruler against it
• Drop each ball in and record the time it takes to pass every 10cm
• Repeat the drops and then average results
• Use magnet to get the balls out
• Plot V against R^2
• Gradient will be equlal to kinetic energy

Question 3

What is the experiment to determine specific heat capacity?

Answer 3

• Weight material to get mass
• Heat the material with electric heater
• Calcuate the change in temperature
• Ammeter and voltmeter connected to the heater to calculate energy used
• Use specific heat capacity equation to calculate specific heat capacity value

Question 4

What is the experimemt to prove brownian motion in a lab?

Answer 4

• Smoke in a glass jar
• Brightly illumianted
• Look under a microscope
• Bright specks will move haphazardly

Question 5

What is the experiment to determine specific latent heat of fusion?

Answer 5

• Set up equal masses of ice in two funnels
• Add a heating coil in one and heat for a certain amont of time
• Using an ammeter, voltmeter and stopwatch calculate the energy used by the heater
• Weight the volume of ice melted from both beakers and calcuate the difference
• Divide the energy transfered by the mass which was melted to calculate the specific latent heat of fusion

Question 6

What is the experiment to determine specific latent heat of vaporisation?

Answer 6

• Set up set mass of water in a beaker
• Heat the water using a heating coil
• Using an ammeter, voltmeter and stopwatch calulate the energy used by the heater
• Weight the beaker to calculate how much water has been evaporated
• Divide energy transfered by the change in mass to calculate the laternt heat of vaporisation

Question 7

What is the experiment to prove Boyle’s law

Answer 7

• Set up a sealed tube of fixed dimensions containg oil and air
• Use a pump to increase the pressure which can be measured uding a bourdon gague
• As you increase the pressure note down the pressure and volume of gas in the tube

Question 8

What is the experiment to prove Charles’ law?

Answer 8

• Immerse a stoppered flask of air in a beaker of water
• Use a short length of tube to connect the stopper to a bourdon gague
• Record the temperature of the water
• Heat the water, stir, and measure the pressure repeatedly until the water boils
• Plot a graph of pressure against temperature
• Absolute zero will be at the point the line crosses the x-axis

Question 9

What experiment can be used to explore circular motion?

Answer 9

A whirling bung
- Equiptment incudes a glass tube, rubber bung, string and some weight
- Thread the string through the tube attaching the bung to one end and the weight to the other
- Make a mark on the string and measure the radius to the bung
- Now spin the bung making sure the mark stays on the edge of the tube
- Time period can be measured using a stopwatch
- Centripetal force should be equal to the weight of the weight