Quick Answer: The Blocks Acrylic, Semi-circular are D-type semicircular blocks of acrylic (PMMA) for refraction experiments, made in 75 x 12 mm and 90 x 15 mm (radius x thickness) sizes. The faces are polished, with a frosted base option that makes the ray path visible.
Last updated: October 2026
Key Features
Acrylic (PMMA)
Semicircular D-type geometry
Polished perpendicular faces
Frosted base option for seeing the ray inside the block
Two sizes: 75 x 12 mm and 90 x 15 mm (radius x thickness)
Technical Specifications
Specification
Value
Material
Acrylic (PMMA)
Shape
Semicircular, D-type
Surface
Polished faces; frosted base option
Sizes (radius x thickness)
75 x 12 mm; 90 x 15 mm
HS Code
9023.00
About This Product
A semicircular block is the usual way to study refraction from a denser to a less dense medium, because a ray aimed at the centre of the flat face leaves the curved face without bending. Students use it with a ray box to measure angles of incidence and refraction, find the critical angle and show total internal reflection. Educational Instrument can arrange export supply of the Blocks Acrylic, Semi-circular to Costa Rica, São Tomé and Príncipe, Qatar, Croatia, Cyprus and Côte d'Ivoire.
Frequently Asked Questions
Which sizes do the Blocks Acrylic, Semi-circular come in?
Two sizes are listed, given as radius x thickness: 75 x 12 mm and 90 x 15 mm.
