Question

an object 4cm in size is placed at 25cm infront of concave mirror of focus length 15cm find the image distance? find the Nature and size of image​

Answer 1

*Question:—

An object 4cm in size is placed at 25cm infront of concave mirror of focus length 15cm find the image distance? find the Nature and size of image.

*Answer:—

• Nature of the size → Magnified.
• Size of image → Real, Inverted and Magnified.

Here is the answer Step by Step explanation:—

→ Height of the Object(H₀) = 4 cm.

→ Object Distance(u) = 25 cm.(negative)

→ Focal Length = 15 cm.(negative)

Using the Mirror's Formula:—

$= > \frac{1}{f} = \frac{1}{v} + \frac{1}{u}$

$⇒ \frac{1}{-15} = \frac{1}{-25} + \frac{1}{v}$

$⇒ v = - 37.5 cm.$

Thus, the image is formed behind the mirror. Since the Distance is Negative, thus the Image is Real.

Thus, Screen is to be placed at a Distance of 37.5 cm behind the Mirror.

Now,

→ Magnification = H₁/H₀

Also,

→ Magnification = -v/u

∴ H₁/H₀ = -v/u

⇒ H₁/4 = - (-37.5)/25

⇒ H₁ = 37.5 × 4/25

⇒ H₁ = 150/25

⇒ H₁ = 6 cm.

Since,

The Size of the Image is greater than the size of the Object, thus the image is Magnified.

Hence,

Characteristics of the Images are is

Real, Inverted and Magnified.