Crookes Radiometer Manufacturer,Supplier and Exporter in India
Product Code : EL-CR-10946
Quick Answer: The Crookes Radiometer is an all-glass radiometer with a 90mm diameter globe that stands 110mm tall. Four vanes inside the vacuum bulb rotate when it is placed near a window or under an incandescent lamp.
Last updated: October 2026
Key Features
All made of glass
Globe 90mm in diameter, standing 110mm tall
Four lightweight vanes suspended inside a vacuum glass bulb
Stronger light gives faster spinning
About This Product
Placed near a window or under an incandescent lamp, the vanes turn when light falls on them. The vacuum matters: with air in the bulb there is too much drag for the vanes to spin, while in a good but incomplete vacuum an effect called thermal transpiration at the vane edges makes the black faces move away from the light. It can stand or hang at a window, showing each ray of sunshine as movement.
Frequently Asked Questions
Q1. How big is the Crookes radiometer? The glass globe is 90mm in diameter and the radiometer stands 110mm tall.
Q2. Why does the Crookes radiometer need a vacuum? If the bulb were full of air, the vanes would not spin because of too much drag. The good vacuum inside the bulb lets them turn in light.
