OLPHY5054AS18QP1V1Q01

Correct Answer: A

Explanation: All electromagnetic waves have speeds in the air of approximately 3 × 10^8 m / s. Option C is wrong because infra-red regions have a shorter wavelength than radio waves thus making the statement untrue. Option D is wrong because Gamma rays have a smaller wavelength than X-rays. Option B is also untrue.  

OLPHY5054AS18QP1V1Q02

Correct Answer: B

Explanation: To measure the circumference of a football you need an instrument that can cover a larger distance and is flexible. Options A and C are used to measure smaller items that require precision to the milli and micrometre. A ruler is unsuitable because it is not flexible.