UPSC Prelims PYQ 2008: Assertion–Reason on radio waves bending in a magnetic...

Consider the following Assertion and Reason:

1. Assertion (A): Radio waves bend in a magnetic field.
2. Reason (R): Radio waves are electromagnetic in nature.

Select the correct answer using the code given below:

1. Both A and R are individually true and R is the correct explanation of A
2. Both A and R are individually true but R is not the correct explanation of A
3. A is true but R is false
4. A is false but R is true

Explanation

Assertion (A) is false

• Radio waves do not bend in a static magnetic field. Because they are composed of photons with no electric charge, they do not experience the Lorentz force that causes charged particles (like electrons) to curve. While light and radio waves can be bent by gravity (gravitational lensing) or very intense nonlinear interactions in specific plasmas, a standard magnetic field does not deflect them.

Reason (R) is true

• Radio waves are indeed electromagnetic in nature. They belong to the long-wavelength, low-frequency portion of the electromagnetic spectrum, consisting of oscillating electric and magnetic fields.

Answer: (d) A is false but R is true