364743 Two thin equiconvex lenses each of focal length \(0.2\;m\) are placed coaxially with their optic centres \(0.5\;m\) apart. Then the focal length of the combination is

364744 The size of the image of an object, which is at infinity, as formed by a convex lens of focal length \(30\;cm\) is \(2\;cm\). If a concave lens of focal length \(20\;cm\) is placed between the convex lens and the image at a distance of \(26\;cm\) from the lens, the new size of the image is

364745 Consider 'beam expander' which consists of two converging lenses of focal lengths 40 \(cm\) and 100 \(cm\) having a common optical axis. A laser beam of diameter 4 \(mm\) is incident on the 40 \(cm\) focal length lens. Then what is the diameter of the final beam (see figure) ?

364746 Two thin lenses are of same focal lengths \((f)\), but one is convex and the other is concave.
When they are placed in contact with each other, the equivalent focal length of the combination will be:

364747 Two identical thin plano-convex glass lenses (refractive index 1.5) each having radius of curvature of \(20\,cm\) are placed with their convex surfaces in contact the centre. The intervening space is filled with oil of refractive index 1.7. The focal length of the combination is

364743 Two thin equiconvex lenses each of focal length \(0.2\;m\) are placed coaxially with their optic centres \(0.5\;m\) apart. Then the focal length of the combination is

364744 The size of the image of an object, which is at infinity, as formed by a convex lens of focal length \(30\;cm\) is \(2\;cm\). If a concave lens of focal length \(20\;cm\) is placed between the convex lens and the image at a distance of \(26\;cm\) from the lens, the new size of the image is

364745 Consider 'beam expander' which consists of two converging lenses of focal lengths 40 \(cm\) and 100 \(cm\) having a common optical axis. A laser beam of diameter 4 \(mm\) is incident on the 40 \(cm\) focal length lens. Then what is the diameter of the final beam (see figure) ?

364746 Two thin lenses are of same focal lengths \((f)\), but one is convex and the other is concave.
When they are placed in contact with each other, the equivalent focal length of the combination will be:

364747 Two identical thin plano-convex glass lenses (refractive index 1.5) each having radius of curvature of \(20\,cm\) are placed with their convex surfaces in contact the centre. The intervening space is filled with oil of refractive index 1.7. The focal length of the combination is

364743 Two thin equiconvex lenses each of focal length \(0.2\;m\) are placed coaxially with their optic centres \(0.5\;m\) apart. Then the focal length of the combination is

364744 The size of the image of an object, which is at infinity, as formed by a convex lens of focal length \(30\;cm\) is \(2\;cm\). If a concave lens of focal length \(20\;cm\) is placed between the convex lens and the image at a distance of \(26\;cm\) from the lens, the new size of the image is

364745 Consider 'beam expander' which consists of two converging lenses of focal lengths 40 \(cm\) and 100 \(cm\) having a common optical axis. A laser beam of diameter 4 \(mm\) is incident on the 40 \(cm\) focal length lens. Then what is the diameter of the final beam (see figure) ?

364746 Two thin lenses are of same focal lengths \((f)\), but one is convex and the other is concave.
When they are placed in contact with each other, the equivalent focal length of the combination will be:

364747 Two identical thin plano-convex glass lenses (refractive index 1.5) each having radius of curvature of \(20\,cm\) are placed with their convex surfaces in contact the centre. The intervening space is filled with oil of refractive index 1.7. The focal length of the combination is

364743 Two thin equiconvex lenses each of focal length \(0.2\;m\) are placed coaxially with their optic centres \(0.5\;m\) apart. Then the focal length of the combination is

364744 The size of the image of an object, which is at infinity, as formed by a convex lens of focal length \(30\;cm\) is \(2\;cm\). If a concave lens of focal length \(20\;cm\) is placed between the convex lens and the image at a distance of \(26\;cm\) from the lens, the new size of the image is

364745 Consider 'beam expander' which consists of two converging lenses of focal lengths 40 \(cm\) and 100 \(cm\) having a common optical axis. A laser beam of diameter 4 \(mm\) is incident on the 40 \(cm\) focal length lens. Then what is the diameter of the final beam (see figure) ?

364746 Two thin lenses are of same focal lengths \((f)\), but one is convex and the other is concave.
When they are placed in contact with each other, the equivalent focal length of the combination will be:

364747 Two identical thin plano-convex glass lenses (refractive index 1.5) each having radius of curvature of \(20\,cm\) are placed with their convex surfaces in contact the centre. The intervening space is filled with oil of refractive index 1.7. The focal length of the combination is

364743 Two thin equiconvex lenses each of focal length \(0.2\;m\) are placed coaxially with their optic centres \(0.5\;m\) apart. Then the focal length of the combination is

364744 The size of the image of an object, which is at infinity, as formed by a convex lens of focal length \(30\;cm\) is \(2\;cm\). If a concave lens of focal length \(20\;cm\) is placed between the convex lens and the image at a distance of \(26\;cm\) from the lens, the new size of the image is

364745 Consider 'beam expander' which consists of two converging lenses of focal lengths 40 \(cm\) and 100 \(cm\) having a common optical axis. A laser beam of diameter 4 \(mm\) is incident on the 40 \(cm\) focal length lens. Then what is the diameter of the final beam (see figure) ?

364746 Two thin lenses are of same focal lengths \((f)\), but one is convex and the other is concave.
When they are placed in contact with each other, the equivalent focal length of the combination will be:

364747 Two identical thin plano-convex glass lenses (refractive index 1.5) each having radius of curvature of \(20\,cm\) are placed with their convex surfaces in contact the centre. The intervening space is filled with oil of refractive index 1.7. The focal length of the combination is