Identify the correct statements from the following in the context of electromagnetic waves.

(A) X-rays are not electromagnetic waves.
(B) Electromagnetic waves are transverse in nature.
(C) Electromagnetic waves can not be polarised.
(D) Electromagnetic waves travel with the speed of light in vacuum.

Choose the correct answer from the options given below:

(B) and (D) only

Explanation:

(A) X-rays are electromagnetic waves of very short wavelength. Hence, this statement is incorrect.

(B) Electromagnetic waves have their electric field and magnetic field vectors oscillating perpendicular to each other and also to the direction of wave propagation. Hence, they are transverse in nature. This statement is correct.

(C) Only transverse waves can be polarised. Since electromagnetic waves are transverse, they can be polarised. Hence, this statement is incorrect.

(D) In vacuum, all electromagnetic waves travel with the same speed, equal to the speed of light, given by

$ c = 3 \times 10^{8}\ \text{m/s} $

Therefore, this statement is correct.

Correct statements: (B) and (D)