Practicals Flashcards
What is the first step when determining the density of a solid?
Use a mass balance to calculate the mass (m) of the solid in kg.
How do you avoid zero error in mass measurements?
Ensure the balance is calibrated.
How do you find the volume of an irregular solid?
Use submersion method with a measuring cylinder and eureka can and calculate the change in water volume.
How do you find the volume of a regular solid?
Measure dimensions with a ruler and use appropriate volume formula
What is the formula for density?
Density (ρ) = mass (m) / volume (v), in kg/m³.
How do you determine the density of a liquid?
Measure the mass of liquid using a zeroed balance and volume with a measuring cylinder, then use the density formula.
How do you measure spring extension?
Measure the difference between the original length and the stretched length.
How is force calculated for a spring?
F = mg, where m is mass in kg and g = 9.81 N/kg.
How is the spring constant found?
From the gradient of a force-extension graph.
What is meant by ‘elastic limit’ on the force-extension graph?
It’s the point beyond which the spring does not return to its original shape.
Why should you take repeated readings and discard anomalies?
To improve accuracy and reliability.
How do you calculate mass using a spring?
Use mg = kx and solve for m.
How do you calculate average speed of a trolley?
Speed = distance / time.
What setup is used for finding acceleration with two light gates?
Use a card on the trolley and two gates to measure initial and final speeds.
How do you find acceleration using one light gate?
Measure time to pass through the gate and calculate v = u + at (u=0).
How do you find acceleration using a stopwatch?
Use s = 1/2 at², rearranged to a = 2s / t².
What is a ripple tank?
A shallow glass tank that uses a paddle to generate water waves.
How is frequency found in a ripple tank?
Count wave peaks passing a point in 60s and divide by 60.
How is wavelength measured?
Use a stroboscope at the same frequency, measure distance between wave maxima.
How do you calculate wave speed?
Use v = fλ.
How can you show wave reflection in a ripple tank?
Let waves hit a wall.
How can you show refraction in a ripple tank?
Place a thick glass sheet to make water shallower, slowing waves.
What measurements are needed for SHC?
Mass, initial and final temperature, voltage, current, and time.
What is the formula for energy transfer?
E = mcΔT.
How is energy calculated from electrical data?
E = IVt.
What formula is used to find specific heat capacity?
c = energy / (mass × temperature change).
What is plotted to determine IV characteristics?
Plot current (I) against voltage (V).
How do you get negative values of V?
Reverse the power supply connections.
What is repeated in the IV practical?
Repeat for three values, take mean of I and V.
What components are tested for IV characteristics?
Fixed resistor, filament lamp, thermistor, LDR, diode.
How do you compare brightness in circuits?
Use 1 to 4 bulbs in series and parallel, observe brightness.
How can you measure brightness quantitatively?
Use a voltmeter; higher PD means greater brightness.
How do you investigate reflection with a mirror?
Use a ray box with a single slit, mark incident and reflected rays, measure angles.
What should you find about the angles?
Angle of reflection = angle of incidence.
How do you investigate refraction through a prism?
Shine a ray through the prism and mark refracted rays for various incident angles.
What graph is plotted for refraction?
Plot sin i against sin r.
What is the first step when determining the density of a solid?
