Physics Paper 1 Experiments Flashcards
(10 cards)
Determining the Acceleration Due to Gravity (g)
Set up a clamp stand with an electromagnet holding a steel ball above a trapdoor connected to a timer.
Measure the height from the bottom of the ball to the trapdoor using a ruler or meter stick.
When the electromagnet is turned off, the timer starts and the ball is released at the same time.
The timer stops when the ball hits and opens the trapdoor.
Repeat for different heights and record the time of fall for each.
Use the time and height data to calculate the acceleration due to gravity.
Plot a graph of height against time squared and find the gradient.
Use repeat measurements and comment on uncertainties in height and time.
Determining the Young Modulus of a Wire
Clamp one end of a thin wire to a fixed point and pass it over a pulley at the other end.
Use a ruler and pointer attached to the wire to measure extension as weights are added.
Measure the original length of the wire.
Use a micrometer to measure the diameter of the wire at multiple points and calculate its cross-sectional area.
Gradually add known masses and record the corresponding extensions.
Calculate stress and strain values and plot a graph of stress against strain.
Determine the Young Modulus from the gradient of the linear section of the graph.
Consider errors such as parallax in reading extension and systematic errors in measurements.
Determining the Resistivity of a Wire
Cut several lengths of a wire and measure each length precisely using a ruler or tape measure.
Use a micrometer to measure the diameter of the wire at different points and calculate the average cross-sectional area.
Connect the wire in a circuit with a power supply, ammeter, and voltmeter.
For each length, measure the current and voltage, and calculate resistance.
Plot a graph of resistance against length to find the gradient.
Multiply the gradient by the cross-sectional area to find the resistivity.
Repeat measurements for accuracy and comment on potential heating effects.
I–V Characteristics of Components
Build a circuit with a power supply, variable resistor, ammeter, voltmeter, and one electrical component (resistor, filament bulb, or diode).
Adjust the variable resistor to change the current and record voltage and current readings.
Reverse the polarity of the power supply to measure negative voltages (especially for the diode).
Plot graphs of current against voltage for each component.
Describe the shape of each graph: straight line for resistor, curved for filament bulb, sharp turn-on point for diode.
Discuss how the resistance changes with current for each component.
Determining Internal Resistance of a Cell
Set up a circuit with a cell, variable resistor, voltmeter across the cell, and ammeter in series.
Change the resistance and record the current and voltage for each setting.
Plot a graph of terminal voltage against current.
The intercept gives the EMF of the cell, and the gradient is equal to the negative internal resistance.
Ensure current is kept low to reduce errors from heating.
Use multiple readings and consider sources of error like contact resistance.
Investigating the Photoelectric Effect
Shine monochromatic light of varying frequency onto a clean metal surface using a photoelectric cell.
Measure the stopping potential needed to stop the photoelectrons using a voltmeter in the circuit.
Record the stopping potential for different light frequencies.
Plot a graph of stopping potential against frequency to determine Planck’s constant or work function.
Show that no electrons are emitted below a certain frequency, regardless of intensity.
This supports the particle theory of light.
Determining Wavelength with a Diffraction Grating
Shine a laser through a diffraction grating onto a screen in a dark room.
Measure the distance from the grating to the screen using a ruler or tape measure.
Measure the distance between the central bright spot and the first or second-order maximum.
Use trigonometry to calculate the angle of diffraction.
Repeat the measurements for different orders and calculate an average wavelength.
Follow laser safety guidelines at all times.
Investigating Stationary Waves
Fix a string to a vibrator (signal generator with a transducer) and pass it over a pulley with a mass for tension.
Vary the frequency of the generator until standing waves form on the string.
Count the number of loops and measure the vibrating length.
Calculate the wavelength based on the number of loops.
Measure the frequency and calculate the wave speed.
Alternatively, compare the speed to the tension and linear mass density of the string.
Double Slit or Interference Experiment
Shine a laser through a double slit to create an interference pattern on a screen.
Measure the distance from the slits to the screen.
Measure the distance between several adjacent bright fringes to find the average fringe spacing.
Record the slit separation from the manufacturer or measure under a microscope.
Use these values to calculate the wavelength of the laser light.
Ensure the laser is securely fixed and used with caution.
Determining the Density of Solids and Liquids
For a regular solid, measure the dimensions using a ruler or micrometer and calculate the volume.
Use a digital balance to measure the mass.
For an irregular solid, measure the volume using water displacement in a measuring cylinder or displacement can.
For a liquid, use a measuring cylinder for volume and a balance to find the mass by subtracting the container’s mass.
Use the mass and volume to calculate the density.
Repeat measurements and calculate uncertainties where appropriate.
