An object is at a distance of 30 cm in front of a concave mirror of focal length 10 cm. The image of the object will be:
1. | smaller in size. |
2. | inverted. |
3. | between the focus and centre of curvature. |
4. | All of the above. |
To a diver inside water, the setting sun will appear at an angle (with the horizontal) of: \(\left[ \mu_w = \frac{5}{4} \right]\)
1. \(53^{\circ}\)
2. \(37^{\circ}\)
3. \(45^{\circ}\)
4. \(60^{\circ}\)
In normal adjustment, the angular magnification of an astronomical telescope is 39. If the length of the tube is 2 m, then the focal length of the objective and eyepiece are respectively,
(1) 195 cm, 5 cm
(2) 190 cm, 10 cm
(3) 20 cm, 180 cm
(4) 10 cm, 190 cm
The following diagram shows a glass sphere of radius 10 cm with a paraxial incident ray. The refractive index of the material of the glass is
1. 2
2. 1.5
3. 1.75
4. 1.3
A convex lens of focal length 10 cm form real image of an object. The distance between the object and the image may be:
(1) 25 cm
(2) 30 cm
(3) 38 cm
(4) 50 cm
A spherical fishbowl of radius 15 cm is filled with water of refractive index . A cat standing outside in the air at a distance of 30 cm from the centre of the fishbowl is looking at the fish. At what distance from the centre would the cat appear to the fish situated at the centre?
1. | 45 cm | 2. | 30 cm |
3. | 15 cm | 4. | 25 cm |
Two convex lenses of focal length X and Y are placed parallel to each other. An object at infinity from the first lens forms its image at infinity from the second lens. The separation between the two lenses should be:
1. | X + Y | 2. | \(\frac{X + Y}{2}\) |
3. | X - Y | 4. | \(\frac{X - Y}{2}\) |
Two plane mirrors are placed perpendicular to each other as shown in the figure. An object O is kept at the angular bisector of the two mirrors. Numbers of images of object O is formed, will be:
1. 4
2. 3
3. 2
4. 1
Two convex lenses of focal lengths 10 cm and 30 cm are kept at a separation of 20 cm. Then the correct statement is:
(1) The effective focal length is 15 cm
(2) Chromatic aberration is minimized
(3) Combination behaves like a convergent lens
(4) All of these
If one surface of a biconvex lens is silvered, then it behaves as
(1) A concave mirror of focal length
(2) A concave mirror of focal length
(3) A convex mirror of focal length
(4) A concave mirror of focal length