Question
In a concave lens, a ray of light emanating from the object parallel to the principal axis of the lens, after refraction :
NEET
Physics
Ray Optics
2026
NEET 2026 (Cancelled)
NEET Physics Question (2026) — Solution
Options
- A. passes through 2F, which is the radius of curvature of the lens.
- B. appears to diverge from the first principal focus.
- C. emerges parallel to the principal axis.
- D. passes through the second principal focus.
Answer
B. appears to diverge from the first principal focus.
Step-by-step solution
According to the rules of refraction for spherical lenses, a ray of light parallel to the principal axis of a concave lens diverges after refraction. When this refracted ray is extended backwards, it appears to diverge from the principal focus located on the same side of the lens as the object. By standard convention, the principal focus on the object side (left side) is termed the first principal focus (F_1). Thus, the ray appears to diverge from the first principal focus. Answer: appears to diverge from the first principal focus.
Related: Physics — Ray Optics · All PYQ Banks