Question

Iron rims of slightly smaller diameter are mounted on the wooden wheels of the cart because:

• A. iron does not allow the wooden wheel to wear off
• B. iron expands on heating and slips over the wooden wheel
• C. iron strengthens the wheel
• D. none of the above

Answer 1

The correct option is B

iron expands on heating and slips over the wooden wheel

1. The iron rim to be mounted on a wooden cartwheel has a slightly smaller diameter than the wooden wheel.
2. The iron rim contracts and holds the wooden wheel very tightly.
3. This prevents the iron rim from loosening its grip over the wooden wheel.

Hence, the correct is an option (B): iron expands on heating and slips over the wooden wheel.