Rainbow colours (VIBGYOR) in physical order from shorter to longer wavelengths: Arrange the following — 1. Orange, 2. Indigo, 3. Red, 4. Blue, 5. Green, 6. Yellow, 7. Violet.

Introduction / Context:
This general science item asks for the standard spectral sequence seen in a rainbow (VIBGYOR). Ordering by wavelength/frequency produces a consistent left-to-right banding.

Given Data / Assumptions:

• Colours (codes): 7 Violet, 2 Indigo, 4 Blue, 5 Green, 6 Yellow, 1 Orange, 3 Red.
• Order needed: physical rainbow order from violet to red.

Concept / Approach:
Recall the acronym VIBGYOR: Violet → Indigo → Blue → Green → Yellow → Orange → Red.

Step-by-Step Solution:

Verification / Alternative check:
Matches the conventional spectrum order from shorter wavelengths (violet) to longer (red).

Why Other Options Are Wrong:

• Any permutation deviating from VIBGYOR mis-orders the spectrum bands.

Common Pitfalls:
Swapping green and yellow; placing red before orange.

Final Answer:
7, 2, 4, 5, 6, 1, 3