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JEE Main 20268 AprilEvening Shift
Exam
JEE Main
Year
2026
Date
8 April
Shift
Evening Shift
Subject
Physics
Chapter
Units and Dimensions

JEE Main 2026 · 8 April · Evening Shift · Physics · Units and Dimensions

A new unit (α) of length is chosen such that it is equal to the...

A new unit (α)(\alpha) of length is chosen such that it is equal to the speed of light in vacuum. What is the distance between Venus and Earth in terms of α\alpha units if light takes 66 min. 4040 s to cover this distance?

Options

  1. A200 α200\,\alpha
  2. B400 α400\,\alpha
  3. C300 α300\,\alpha
  4. D500 α500\,\alpha

Correct answer

B. 400 α400\,\alpha

Step-by-step solution

Given that the new unit of length α\alpha is chosen such that the speed of light in vacuum is 1 α/s1\,\alpha/\text{s}.

Time taken by light to cover the distance, t=6 min 40 st = 6\text{ min } 40\text{ s}

t=6×60 s+40 s=400 st = 6 \times 60\text{ s} + 40\text{ s} = 400\text{ s}

Distance between Venus and Earth is given by d=c×td = c \times t

d=1 α/s×400 s=400 αd = 1\,\alpha/\text{s} \times 400\text{ s} = 400\,\alpha

Answer: 400 α400\,\alpha
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