Practicals

Answer 1

Circuit and apparatus setup

Fix one end of the string (or wire) to a mechanical oscillator (signal generator + pulley + hanging mass) and the other end to the pulley where varying weights provide tension 𝑇

Use a frequency generator and lamp–pointer to produce transverse waves; measure wavelength 𝜆 by the distance between bright fringes or use a traveling‐wave method with a marker.

Varying tension

Change the hanging mass to set different tensions
𝑇 = 𝑚𝑔, for each tension, keep frequency constant (e.g. 50 Hz) and measure corresponding wavelength 𝜆

Varying linear mass density (optional extension)

If required, repeat with strings of different linear densities 𝜇 (e.g. nylon vs steel) to see effect on speed.

Data processing and graph

Calculate wave speed
𝑣 =𝑓𝜆, for each tension.

Plot 𝑣^2 (y‑axis) against 𝑇 (x‑axis); the gradient gives 1/𝜇

Theoretical relationship

Use the theory
𝑣 = sqrt(𝑇/𝜇)
​
A straight‑line graph of 𝑣^2 vs 𝑇 confirms this, since
𝑣^2 = T/μ.

Uncertainty and evaluation (1 mark)

Quote uncertainties for 𝑓, 𝜆, 𝑇, and string diameter (if measuring 𝜇)

Discuss systematic errors (e.g. slippage on the pulley, non‑uniform string, parallax in reading 𝜆 and suggest improvements (e.g. use digital frequency meter, strobe lamp for clearer nodes, more tension values).