GCSE Physics Practical Notes (AQA) Paper 1 And 2

Tips for Practical Exams

• Variables: Understand the three types of variables:

  • Independent Variable: The variable you change.
  • Dependent Variable: The variable that changes as a result; this is measured.
  • Controlled Variables: Variables kept constant to ensure accuracy.

• Equipment Identification: Always specify the equipment used for measurements (e.g., "measure the length using a ruler"). This can earn you extra marks.

• Measurement Accuracy: Discuss methods to reduce errors and uncertainties, like aligning your eye level with the measurement mark (to avoid parallax error).

• Repeat Measurements: Encourage conducting multiple readings to calculate an average for more reliable results.

• Bullet Point Format: Writing in bullet points is encouraged; clarity aids the examiner in tracking your points.

• Proper Language: Use full sentences and formal language in your responses, avoiding overly casual phrases.

Physics 1: Specific Heat Capacity

• Definition: Specific Heat Capacity (SHC) is the energy required to raise 1 kg of a substance by 1°C.
• Experiment Setup: Insert an electrical heater into a beaker of water or a block of metal.
• Measurements:
  • Record the mass and initial temperature with a thermometer.
  • Measure the temperature change every 20 seconds:
  • Dependent variable: Temperature.
• Power Calculations:
  • Use an ammeter and voltmeter to determine current and potential difference (PD).
  • Calculate power as: P = IV (where $I$ is current and $V$ is voltage).
• SHC Formula:
  • Rearrange to: SHC = \frac{Q}{m \Delta T} (where $Q$ is energy in joules, $m$ is mass, and $\Delta T$ is temperature change).

Physics 2: Resistance of a Wire

• Objective: Investigate the relationship between the length of a wire and its resistance.
• Materials: Use constantan wire for consistent resistance when heated.
• Setup Details:
  • Connect wires to a battery, an ammeter (in series), and a voltmeter (in parallel).
• Procedure:
  • Change the distance between crocodile clips to vary wire length; measure with a meter rule.
  • Calculate resistance using Ohm's Law: R = \frac{V}{I} .
• Resulting Relationship: Plot resistance against length; expect a straight line through the origin demonstrating direct proportionality.

Physics 3: IV Characteristics

• Experiment Purpose: Determine how current changes with varying potential difference (PD).
• Setup:
  • Connect a fixed resistor with a variable resistor in series.
  • Use voltmeter (parallel) and ammeter (series) to measure PD and current, respectively.
• Data Collection: Reverse the battery for negative PD and current values.
• Graphing Results:
  • For a fixed resistor: expect a straight line (ohmic).
  • For a filament bulb: expect a curve reflecting nonlinear resistance.
  • A diode allows current in one direction only; exhibit high resistance in the reverse direction.

Physics 4: Density

• Finding Density of Solids:
  • Measure mass using a top pan balance.
  • For regular shapes, measure dimensions to calculate volume; for irregular shapes, use water displacement.
• Density Calculation Formula: \text{Density} = \frac{\text{Mass}}{\text{Volume}} .
• Solution Density: Pour solution into a zeroed measuring cylinder and measure mass.
• Example: Pure water's density is 1 g/cm³; a 1.2 g/cm³ salt solution indicates 0.2 g/cm³ concentration.

Physics 5: Springs

• Objective: Determine the spring constant.
• Setup: Fix one end of a spring; hang slotted masses to measure extension.
• Measurement of Extension: Track extension accurately using a ruler aligned with the spring's bottom.
• Force Calculation: F = mg (with $g = 9.8 ext{ m/s}^2$).
• Data Presentation: Plot force against extension; the gradient indicates the spring constant (k).

Physics 6: Newton's Second Law

• Purpose: Verify F = ma using slotted masses attached to a trolley.
• Setup: Place the trolley on a track with a string over a pulley; measure acceleration through light gates or stopwatch.
• Maintain Mass: Keep total mass constant by balancing added masses on the trolley.
• Force Calculation: Again F = mg ; plot force vs. acceleration to yield a direct proportional relationship.

Physics 7: Waves

• Ripple Tank Experiment:
  • Project imagery of waves using light; measure wavelength by counting 10 waves and dividing.
  • Introduce frequency changes to analyze wavelength adjustment; use wave speed equation: V = f\lambda .
• Stationary Waves on String:
  • Adjust frequency to achieve a simple stationary wave; length to pulley equals half the wavelength.

Physics 8: Infrared Absorption

• Leslie Cube Experiment: Fill with hot water, measure infrared emission from various surfaces.
• Key Findings: Matte black is best for emitting and absorbing infrared; shiny surfaces reflect well.

Physics 9: Insulation

• Triple Science Only: Wrap beakers of hot water in different insulating materials and record temperature loss over time.

Physics 10: Refractive Index

• Measurement Process: Shine light into a block; mark entry and exit points to measure angles of incidence and refraction.
• Calculations: For various angles of incidence, calculate \frac{\sin(i)}{\sin(r)} to find a constant for the refractive index.