As shown in the figure, a block is placed in front of a convex lens. Choose the most appropriate image of the block from the following options:





Step 1: The image formation by a convex lens depends on the object's position relative to the focal point and the lens. - If the object is placed between the focus and the lens, the image formed will be virtual, upright, and magnified.
- If the object is placed beyond twice the focal length, the image formed will be real, inverted, and diminished.
Step 2: In this case, the block is placed in front of the convex lens at a distance beyond \( 2F \) (twice the focal length), so the image formed will be real, inverted, and diminished.
Step 3: According to the given options, the image that fits the description of a real, inverted, and diminished image is Option 2.
A source and an observer move away from each other with same velocity of 10 m-1 with respect to the ground. If the observer finds the frequency of sound coming from the source as 1980 Hz, then the actual frequency of the source is (speed of sound in air = 340 ms-1)
Two convex lenses of focal lengths 20 cm and 30 cm are placed in contact with each other co-axially. The focal length of the combination is: