The focal length of a convex lens is 40 cm and the size of the inverted image formed is half of the object. The distance of the object is:
1. | 60 cm | 2. | 120 cm |
3. | 30 cm | 4. | 180 cm |
The condition of minimum deviation is achieved in an equilateral prism kept on the prism table of a spectrometer. If the angle of incidence is \(50^{\circ}\), the angle of deviation is:
1. \(25^{\circ}\)
2. \(40^{\circ}\)
3. \(50^{\circ}\)
4. \(60^{\circ}\)
An object is placed 20 cm in front of a concave mirror of a radius of curvature 10 cm. The position of the image from the pole of the mirror is:
1. 7.67 cm
2. 6.67 cm
3. 8.67 cm
4. 9.67 cm
The angle of minimum deviation for a glass prism of refractive index \(\mu = \sqrt{3}\) equals the refracting angle of the prism. The angle of the prism is:
1. \(30^{\circ}\)
2. \(60^{\circ}\)
3. \(90^{\circ}\)
4. \(45^{\circ}\)
The angle of a prism is A and one of its refracting surfaces is silvered. Light rays falling at an angle of incidence 2A on the first surface return through the same path after suffering reflection at the second (silvered) surface. The refractive index of the material is:
1. 2sinA
2. 2cosA
3. cosA
4. tanA
The correct statement is:
1. | The intermediate image in a compound microscope is real, erect and magnified |
2. | Intermediate image in a compound microscope is real, inverted, but diminished |
3. | Intermediate image in a compound microscope is virtual, erect and magnified |
4. | Intermediate image in a compound microscope is real, inverted and magnified |
A ray of light is incident on an equilateral glass prism placed on a horizontal table as shown. For minimum deviation, a true statement is:
1. | PQ is horizontal |
2. | QR is horizontal |
3. | RS is horizontal |
4. | Either PQ or RS is horizontal |
When a ray of light falls on a given plate at an angle of incidence \(60^{\circ}\), the reflected and refracted rays are found to be normal to each other. The refractive index of the material of the plate is:
1. | \(\frac{\sqrt{3}}{2} \) | 2. | \(1.5 \) |
3. | \(1.732 \) | 4. | \( 2\) |
A thin rod of length \(\frac{f}{3}\) lies along the axis of a concave mirror of focal length \(f\). One end of its magnified, real image touches an end of the rod. The length of the image is:
1. \(f\)
2. \(\frac{f}{2}\)
3. \(2f\)
4. \(\frac{f}{4}\)
A thin equiconvex lens of power P is cut into three parts A, B, and C as shown in the figure. If P1, P2, and P3 are powers of the three parts respectively, then:
1. | \(P_1=P_2=P_3\) | 2. | \(P_1>P_2=P_3\) |
3. | \(P_1<P_2=P_3\) | 4. | \(P_2=P_3=2P_1\) |