What is the magnification produced by a concave lens if the object is placed at
Practice Questions
Q1
What is the magnification produced by a concave lens if the object is placed at a distance of 30 cm and the focal length of the lens is 15 cm? (2022)
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Questions & Step-by-Step Solutions
What is the magnification produced by a concave lens if the object is placed at a distance of 30 cm and the focal length of the lens is 15 cm? (2022)
Step 1: Identify the given values. The object distance (u) is -30 cm (negative because it is on the same side as the object) and the focal length (f) is -15 cm (negative for a concave lens).
Step 2: Use the lens formula: 1/f = 1/v + 1/u. Substitute the values: 1/(-15) = 1/v + 1/(-30).
Step 3: Simplify the equation: 1/(-15) = 1/v - 1/30.
Step 4: Find a common denominator for the right side: 1/v = 1/(-15) + 1/30.
Step 5: Calculate 1/(-15) + 1/30. The common denominator is 30, so: 1/(-15) = -2/30. Therefore, 1/v = -2/30 + 1/30 = -1/30.
Step 6: Solve for v: v = -30 cm. This means the image is formed 30 cm on the same side as the object.
Step 7: Use the magnification formula: m = -v/u. Substitute the values: m = -(-30)/(-30).
Step 8: Simplify the magnification: m = 1.
Step 9: Since the magnification is positive, it indicates that the image is upright and the absolute value of the magnification is 1.
