The focal length of a convex lens is 25cm.At what distance from the op...
Focal length =25 cm so, distance between from optical center to focus is 25 cm and2f = 50 cmIf we place image between optical center and focus between 25 cm to 0 cm, Image formed is virtual magnified and larger in size and formed beyond the 25 cm of the lens on same side of lens.
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The focal length of a convex lens is 25cm.At what distance from the op...
V/u = 2 positive .since the image is virtual .since image is on the side of object :.v= 2u negative ,f = 25 cm positive . From relation 1/f= 1/v_1/u , ..answer will be obtained ..put the value in this relation..
The focal length of a convex lens is 25cm.At what distance from the op...
Calculating the Object Distance for Virtual Image Formation
- Given: Focal length (f) = 25 cm
- Image magnification (m) = 2
Formula for Magnification:
m = - (v/u)
Formula for Focal Length:
1/f = 1/v + 1/u
Calculating Image Distance (v):
Given that the image formed is virtual and twice the size of the object, the magnification (m) is 2. Therefore, m = -2.
Using the magnification formula, we have:
-2 = - (v/u)
Calculating Object Distance (u):
Substitute the given focal length (f = 25 cm) into the formula for focal length:
1/25 = 1/v + 1/u
1/v = 1/25 - 1/u
Now, substitute the value of magnification into the magnification formula:
-2 = - (v/u)
v = -2u
Putting it all together:
Substitute v = -2u into the focal length formula:
1/25 = 1/(-2u) + 1/u
1/25 = -2/u + 1/u
1/25 = -1/u
u = -25 cm
Therefore, the object should be placed at a distance of 25 cm from the optical centre of the convex lens to obtain a virtual image that is twice the size of the object.
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