1. | \(4.5\) cm | 2. | \(20.0\) cm |
3. | \(9.37\) cm | 4. | \(6.67\) cm |
A lens forms an image of a point object placed at distance \(20\) cm from it. The image is formed just in front of the object at a distance \(4\) cm from the object (and towards the lens). The power of the lens is:
1. \(-2.25\) D
2. \(1.75\) D
3. \(-1.25\) D
4. \(1.4\) D
The distance between the object and its real image formed by a concave mirror is minimum when the distance of the object from the centre of curvature of the mirror is: [\(f\rightarrow\) focal length of the mirror]
1. | Zero | 2. | \(\dfrac{f}{2}\) |
3. | \(f\) | 4. | \(2f\) |
A point object \(O\) is placed at a distance \(20\) cm from a biconvex lens of the radius of curvature \(20\) cm and \(\mu=1.5.\) The final image produced by lens and mirror combination will be at:
1. | \(10\) cm from the mirror |
2. | \(20\) cm from the lens |
3. | \(-20\) cm from the lens |
4. | \(-15\) cm from the mirror |
A person can see objects clearly between 1 m and 3 m. The power of lens required to correct near point will be:
1. 2.5 D
2. + 3 D
3. + 1.5 D
4. 1.75 D
In the case of a compound microscope, the image formed by the objective lens is:
1. | Virtual, erect, and diminished. |
2. | Real, erect, and magnified. |
3. | Virtual, inverted, and enlarged. |
4. | Real, inverted, and enlarged. |
1. \(0.4\)
In the following diagram, what is the distance \(x\) if the radius of curvature is \(R= 15\) cm?
1. | \(30\) cm | 2. | \(20\) cm |
3. | \(15\) cm | 4. | \(10\) cm |
In the diagram shown below, the image of the point object \(O\) is formed at \(l\) by the convex lens of focal length \(20\) cm, where \(F_1\) and \(F_2\) are foci of the lens. The value of \(x'\) is:
1. | \(10\) cm | 2. | \(20\) cm |
3. | \(30\) cm | 4. | \(40\) cm |
A glass slab is placed with the right-angled prism as shown in the figure. The possible value of \(\theta\) such that light incident normally on the prism does not pass through the glass slab is:
1. | \(30^\circ\) | 2. | \(37^\circ\) |
3. | \(45^\circ\) | 4. | Both (1) & (2) |