Subject: Physics (Optics)

Topic: Refraction through a Convex Lens (Image Formation)

Step 1 (Governing Law & Principle): [0.25 Mark]

The image formation by a convex lens is governed by the property of lateral and longitudinal inversion. According to the sign convention and ray optics principles, a convex lens forms a real and inverted image of an object placed beyond its focal length ($f$).

Step 2 (Step-by-Step Logical Deduction): [0.50 Mark]

• The object is a vertical arrow with a horizontal line and a ball.
• A convex lens produces an image that is inverted both vertically and horizontally (180° rotation).
• Let the object coordinates be $(x, y)$. The image coordinates $(x', y')$ are given by: $$x' = -m \cdot x$$ $$y' = -m \cdot y$$ where $m$ is the magnification. Since the image is real and inverted, $m$ is negative.
• Consequently, the vertical arrow pointing upwards will point downwards.
• The horizontal line attached to the arrow will undergo lateral inversion, causing the ball (originally on one side) to appear on the opposite side relative to the vertical axis.

Step 3 (Final Concluded Answer): [0.25 Mark]

The correct representation is the option where the arrow points downwards and the ball is shifted to the opposite side of the horizontal line. (Correct Option: C)

💡 EL10 Concept Insight:

Think of the lens as a mirror that flips everything upside down and turns it around; if you point your finger up and to the right, the lens "sees" it as pointing down and to the left!