PhysicsUK Connections

Connections.EXPLORE · CONNECT · UNDERSTAND YOUR COURSEOCR A · AS Physics Browse topics →
All apps ↗
55 ideas · 69 connections
Wave frequency and photon energy Measuring motion without hiding uncertainty Small length errors can matter greatly in density Stress and pressure share units, but describe different loading Measuring Young modulus accurately Why wire diameter matters in resistivity One photon supplies one electron’s energy LED voltage links electrical and photon energy A Planck-constant experiment needs uncertainty analysis Instrument choice sets the measurement limits Waves4.4 Quantum physics4.5 Implementing1.1.2 Measurements and uncertainty2.2.1 Kinematics3.1.1 Density and pressure3.2.4 Mechanical properties of matter3.4.2 E.m.f. and potential difference4.2.2 Resistivity4.2.4 Photons4.5.1 The photoelectric effect4.5.2
100%
PHYSICSUK CONNECTIONS
Physics connection

A Planck-constant experiment needs uncertainty analysis

OCR A AS Physics · Two ideas, one explanation

A graph can estimate Planck’s constant, but the reliability of the estimate depends on the voltage measurements and the gradient range allowed by them.

h = e × gradient of V against f

Follow the reasoning

  1. Plot the measurements with appropriate uncertainty bars.
  2. Draw a best-fit line and a justified worst acceptable line.
  3. Transfer the fractional gradient uncertainty to h.
Specification outcomes (4)
  • 4.5.1(e)(i) Use LEDs and eV = hc / λ to estimate the value of Planck’s constant.
  • 4.5.1(e)(ii) Determine Planck’s constant using different coloured LEDs experimentally.
  • 2.2.1(a) Understand systematic errors (including zero errors) and random errors in measurements.
  • 2.2.1(d) Use graphical treatment of errors and uncertainties, including line of best fit, worst line, absolute and percentage uncertainties, and percentage difference.
Open the official OCR AS specification ↗

H156 v2.0 · May 2026

See it in an exam

A curated collection of checked examples. Coverage is growing; this is not a complete past-paper catalogue.

Put the ideas to work

More practice is on its way

No PhysicsUK question linked yet. New eligible questions appear here as the bank grows.