Question
The speed of light in vacuum is taken as unity. If light takes 6 min 40 s to reach the Earth from the Sun, the distance between the Sun and the Earth in new unit is :
NEET
Physics
Units and Dimensions
2026
NEET 2026 (Cancelled)
NEET Physics Question (2026) — Solution
Options
- A. 3 10^ 8
- B. 500
- C. 3 10^ 10
- D. 400
Answer
D. 400
Step-by-step solution
Speed of light in vacuum, c = 1 unit/s. Time taken by light to reach the Earth from the Sun, t = 6 min 40 s. Converting time into seconds: t = 6 60 + 40 = 360 + 40 = 400 s. Distance between the Sun and the Earth is given by: d = c t d = 1 400 = 400 new units. Answer: 400
Related: Physics — Units and Dimensions · All PYQ Banks