GCSE Physics Paper 1 Required Practicals

• What are some common errors that lead to inaccurate density values in the density practical?

  Not zeroing balances and so including the mass of the beaker in a measurement or measuring the mass of a wetted solid instead of dry.
• What measurements are taken to find the density of a liquid, and what apparatus are used for each measurement?

  Measure the volume of liquid (with a measuring cylinder). Place a beaker on a balance. Zero the balance. Pour the liquid into the beaker and measure the mass of the liquid (with the balance).
• What measurements are taken to find the density of an irregular solid object, and what apparatus are used for each measurement?

  Measure the mass (using a balance). Measure the volume by lowering the solid into a filled eureka can and collecting the displaced water in a measuring cylinder. The volume of water in the measuring cylinder = volume of the solid.
• What measurements are taken to find the density of a regular solid object, and what apparatus are used for each measurement.

  Measure the length, width and height (with a ruler). Multiply together to find the volume. Measure the mass (with a balance).
• How is density calculated from the measurements taken in any density practical?

  Density = mass ÷ volume.
• What apparatus is used to find the density of a liquid?

  Balance, measuring cylinder, beaker.
• What apparatus is used to find the density of an irregular solid object?

  Balance, eureka can, measuring cylinder.
• What apparatus is used to find the density of a regular solid object?

  Balance, 30 cm ruler.
• In the wire length resistance practical what is used to connect the resistance wire to the circuit measuring resistance?

  A crocodile clip.
• What apparatus are used in all of the electricity practicals?

  Battery, switch, variable resistor, connecting wires, ammeter, voltmeter.
• In the series/parallel resistors practical what graphs should you plot, what shape should they be, and why?

  Plot total circuit resistance (y-axis) against number of resistors (x-axis). Plot one graph for series resistors, the other for parallel. The series graph is a straight line showing that resistance is directly proportional to the number of resistors. The parallel graph is a curve showing that increasing the number of resistors, decreases the total resistance of the circuit.
• What measurements are taken in the parallel/series resistors practical, and what apparatus is used to take each measurement?

  Using a single resistor, use the variable resistor to produce a potential difference of 1 V (measured with a voltmeter) and measure the current (with an ammeter). Switch off. Repeat the measurements for 2, 3, and 4 identical resistors in series. Make sure the voltmeter is across all of the resistors being tested. Then repeat the measurements for 2, 3, and 4 identical resistors in parallel. Use the measurements to calculate resistance for each resistor combination.
• In the parallel/series resistors practical, and resistance and length practical, how is resistance calculated from the measurements taken?

  Resistance = potential difference ÷ current
• In the I-V graphs (characteristics) practical what shape graph should you get for a diode and why?

  Curve but only in the positive part of the graph. The diode has a very high resistance in the reverse direction. Current will only flow through a diode in one direction.

  
• In the I-V graphs (characteristics) practical what shape graph should you get for a filament lamp and why?

  Curve. ICITIR. Increasing the Current, Increases the Temperature, which Increases the Resistance.

  
• In the I-V graphs (characteristics) practical what shape graph should you get for a resistor at constant temperature and why?

  Straight line through the origin. Current is directly proportional to potential difference as an Ohmic resistor at constant temperature has a constant resistance.

  
• For every measurement in a practical what should you do to reduce the effect of random error?

  Repeat the measurement twice and calculate a mean of the three measurements.
• Why do you reverse the connections to the battery in the I-V graphs (characteristics) practical?

  To reverse the direction of the current through the component being tested.
• What measurements are taken in the I-V graphs (characteristics) practical, and what apparatus are used to make each measurement?

  Adjust the variable resistor to produce a potential difference of 1 V (measured with a voltmeter) across the component being tested. Measure the current (with an ammeter). Switch off. Repeat the measurements for 2, 3, 4, and 5 V. Reverse the connections on the battery. Repeat the measurements for - 1, -2, -3, -4, -5 V.
• What is the hazard and risks, and what precautions are taken in electricity practicals?

  Hazard is high currents, risks are heating causing components/wires to melt or burn if touched. Precautions are to use low currents and switch off between measurements to reduce heating.
• What graph is plotted in the resistance of different lengths of wire practical? What shape of graph do you expect, and what does this mean about the relationship between resistance and length?


  Plot resistance (y-axis) against length (x-axis). The graph should be a straight line through the origin. This shows that resistance is directly proportional to length.
• What are the control variables in the resistance of different wire lengths practical?

  Material of the wire, diameter of the wire, temperature of the wire.
• In electricity practicals what must happen between every measurement and why?

  The circuit must be switched off to reduce heating of the component. This is because changing the temperature of the component can effect its resistance.
• What measurements are taken in the resistance of different wire lengths practical, and what apparatus are used for each measurement?

  Measure 10 cm length of wire (with a metre ruler), measure the potential difference across (with a voltmeter) and the current through (with an ammeter) the wire. Switch off. Repeat the measurements for 20, 30, 40, 50, 60 and 70 cm of wire. Use the measurements to calculate resistance.
• Draw or describe the circuit to measure potential difference (voltage) and current in all of the electricity practicals.

  Battery in series with an ammeter, variable resistor, switch and the component being tested. Voltmeter in parallel with the component being tested.

  
• What graph is plotted in the thermal insulation practical, and how is it used to compare the effectiveness of different insulators?

  Plot temperature (y-axis) against time (x-axis). The smallest change in temperature in the same time is the best insulator.
• What is the hazard and risk, and what precautions are taken to reduce the risk in the thermal insulation practical?

  Hazard is the hot water, risk of spilt hot water causing burns, precaution is to use a funnel to pour hot water from the kettle and measuring cylinder.
• What are two control variables in the thermal insulation practical?

  Same volume of water, same starting temperature.
• What measurements are taken in the thermal insulation practical, and what apparatus are used for each measurement?

  Measure 50 ml hot water from the kettle (with a measuring cylinder) and pour into the beaker. Measure the temperature of water in the beaker (with a thermometer) every minute (with a stop clock) for 10 minutes.
• What apparatus are needed to investigate the effectiveness of thermal insulators?

  Thermal insulators, kettle, beaker, lid, stop clock, thermometer, funnel, heat proof mat, measuring cylinder.
• What graph is plotted in the specific heat capacity experiment, and how is the graph used to find the specific heat capacity of the material?

  Plot temperature (y-axis) against energy supplied (x-axis). The straight bit of the graph is used to find the gradient. The specific heat capacity is then 1 ÷ (gradient x mass of the material).
• If insulation is not used in the specific heat capacity experiment, is the value of specific heat capacity too high or too low?

  Too high. This is because more of the energy transferred by the heater heats the surroundings compared to if insulation was used.
• Why is insulation used in the specific heat capacity experiment?

  To reduce energy transfer to the surroundings. This makes the specific heat capacity value more accurate.
• What measurements are taken in the specific heat capacity experiment, and what apparatus are used for each measurement?

  Measure the temperature of the material (with a thermometer) and the energy supplied to the heater (with a Joulemeter) every minute (with a stop clock) for 10 minutes. Measure the mass of the material (with a balance).
• What apparatus are needed to measure the specific heat capacity of a material?

  Power supply, joulemeter, heater, thermometer, material to test, insulation, stopclock, balance