If the magnification produced by a lens is +2, then the image is:
erect, virtual and larger than the object.
Understanding Lens Magnification: Analyzing m = +2
The question asks about the characteristics of an image formed by a lens when the magnification (\(m\)) is given as +2. Magnification is a key property that describes the image's orientation and size relative to the object.
What is Lens Magnification?
Magnification (\(m\)) for a lens is defined as the ratio of the image height (\(h_i\)) to the object height (\(h_o\)). Mathematically, it is expressed as:
\(m = \frac{\text{Image Height}}{\text{Object Height}} = \frac{h_i}{h_o}\)
The value and sign of the magnification provide specific information about the image characteristics.
Interpreting the Magnification Value (m = +2)
Let's break down the given magnification value, m = +2:
-
Sign Interpretation: The sign of the magnification indicates the orientation of the image.
- A positive sign (like the '+' in +2) signifies that the image is erect. This means the image is oriented in the same direction as the object (e.g., both are upright).
- A negative sign would indicate an inverted image.
-
Magnitude Interpretation: The numerical value (absolute value) of the magnification indicates the relative size of the image.
- Here, the magnitude is \(|m| = |+2| = 2\).
- Since the magnitude is greater than 1 (\(2 > 1\)), the image is magnified, meaning it is larger than the original object.
- A magnitude less than 1 would mean a diminished (smaller) image, and a magnitude equal to 1 would mean an image of the same size.
- Image Nature (Virtual vs. Real): For lenses, an erect image (positive magnification) is generally a virtual image. Virtual images are formed where light rays only *appear* to converge and cannot be projected onto a screen. They are typically formed on the same side of the lens as the object. In contrast, inverted images (negative magnification) are usually real images.
Summary of Characteristics for m = +2
Combining these points for a magnification of m = +2:
- The image is erect (due to the positive sign).
- The image is larger than the object (due to the magnitude being 2).
- The image is virtual (because it is erect).
Therefore, the correct description of the image is erect, virtual, and larger than the object.
Important Questions from Optics
Who was the first one to use a glass prism to obtain the spectrum of sunlight?
Twinkling of stars is due to:
In which a convex mirror is used?
A. Rear View mirrors in vehicles
B. Glass windows
C. Makeup Mirror
D. Kaleidoscope
An object is placed 10 cm in front of a lens. The image formed is real, inverted and of same size as the object. What is the focal length and nature of the lens?
The power of a lens is -2.5 D. The type of lens and its focal length are respectively:
