Question

If radius of a circle is halved then, ________________.

• A. Diameter will be doubled
• B. Diameter will be halved
• C. Diameter will increase
• D. Diameter will be same

Answer 1

The correct option is B Diameter will be halved

If the diameter of a circle is doubled, then its radius is also doubled.
Eg. If diameter of a circle ie 6 cm then radius $=\frac{6}{2}=3$ cm
If the diameter is doubled i.e. if diameter $=2\times 6=12$ cm
then radius is $\frac{12}{2}=6$ cm
Hence the radius is also doubled.

So if the radius is halved, diameter is also halved.