A lens forms a real image that is twice the size of the object. If the object di
Practice Questions
Q1
A lens forms a real image that is twice the size of the object. If the object distance is 10 cm, what is the image distance? (2021)
10 cm
15 cm
20 cm
25 cm
Questions & Step-by-Step Solutions
A lens forms a real image that is twice the size of the object. If the object distance is 10 cm, what is the image distance? (2021)
Step 1: Understand the problem. We have a lens that creates a real image that is twice the size of the object.
Step 2: Identify the object distance (u). The object distance is given as 10 cm. Since we use the convention that object distance is negative, we write u = -10 cm.
Step 3: Use the magnification formula. The magnification (m) is given as 2 because the image is twice the size of the object. The formula is m = -v/u.
Step 4: Substitute the known values into the magnification formula. We have m = 2, u = -10 cm, so we write 2 = -v / (-10).
Step 5: Simplify the equation. This gives us 2 = v / 10.
Step 6: Solve for v (image distance). Multiply both sides by 10 to get v = 2 * 10 = 20 cm.
Step 7: Conclude that the image distance (v) is 20 cm.
Lens Formula – Understanding the relationship between object distance (u), image distance (v), and magnification (m) in lens systems.
Magnification – The ratio of the height of the image to the height of the object, which can also be expressed in terms of distances.