Here are some experiments suitable for investigations that you can carry out with minimal financial outlay.

The experiments include:

Air cell

Compound pendulum

Current balance

Diffraction grating to find n for water

Moment of inertia

Moment of inertia (broom stick about different axes)

Optical activity

Permittivity Reed Switch

Permittivity EHT supply

Resonant frequency of a wire

Download them all as a zip file here