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NEET2026PhysicsChapterActual

For a convex lens, if an incident ray of light passes through its first principal focus before striking the lens, the refracted ray will :

Options

  1. Apass through the second principal focus on the other side of the lens.
  2. Bemerge parallel to the principal axis.
  3. Cpass undeviated through the optical centre of the lens.
  4. Dretrace its path back along the same line.

Correct answer

B. emerge parallel to the principal axis.

Step-by-step solution

According to the rules of image formation by a convex lens, an incident ray of light passing through the first principal focus of the lens becomes parallel to the principal axis after refraction. This is based on the principle of reversibility of light, as a ray parallel to the principal axis passes through the principal focus after refraction. Answer: emerge parallel to the principal axis.

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