How do woollen clothes keep us warm?
Woollen clothes trap air inside it. Air is a poor conductor of heat. The trapped air in woollen clothes does not allow body heat to release outside the body and keeps us warm.
Why do we wear dark coloured clothes in winter? Why do we wear light coloured clothes in summer? How do woollen clothes keep us warm during winter? [3 MARKS]
Sweaters knitted of acrylic keep us as warm as woollen sweaters.