Q1.Refractive index of an optical medium changes with
1. the nature of the medium.
2. the change in the angle of incidence of the ray.
3. colour of the incident ray.
Select the correct answer using the code given below:
(a) 1 and 3 only
(b) 2 and 3 only
(c) 1 and 2 only
(d) 1, 2 and 3Q2. An optician prescribes a lens of power = – 0.5 dioptre. The corresponding lens must be a
(a) convex lens of focal length 2 m
(b) convex lens of focal length 50 cm
(c) concave lens of focal length 2m
(d) concave lens of focal length 50 cmQ3. Which one of the following does not affect the motion of a moving electron?
(a) Electric field applied in the direction of motion
(b) Magnetic field applied in the direction of motion
(c) Electric field applied perpendicular to the direction of motion
(d) Magnetic field applied perpendicular to the direction of motion Q4. The rating of an electric lamp is 110V. To use it on 220 V, one will have to use which one of the following?
(d) Generator Q5. Net charge in a current-carrying conductor is
(a) always positive
(b) always negative
(d) either positive or negativeQ6. The direction of magnetic field at a point due to an infinitely long wire carrying current is
(a) parallel to the current
(b) antiparallel to the current
(c) along the perpendicular drawn from a point on the wire
(d) perpendicular to the plane containing the conductor and the pointQ7. The resistance of a wire is 10 W. If it is stretched ten times, the resistance will be
(a) 1 ohm
(b) 10 ohm
(c) 100 ohm
(d) 1000 ohmQ8. Metal used to make wires for safety fuses must have
(a) very low resistivity and high melting point
(b) high resistivity and low melting point
(c) low resistivity and low melting point
(d) high resistivity and high melting pointQ9. Electromagnetic radiations are emitted by which of the following?
(a) Only by radio and television transmitting antennas
(b) Only by bodies at temperature higher than their surroundings
(c) Only by red-hot bodies
(d) By all bodies Q10. The penetrating power of X-rays can be increased by
(a) increasing the current in the filament
(b) decreasing the potential difference between the cathode and the anode
(c) decreasing the current in the filament
(d) increasing the potential difference between the cathode and the anodeQ11. What are the types of bonds present in CuSO4 .5H2O?
(a) Electrovalent and covalent
(b) Electrovalent and coordinate covalent
(c) Electrovalent, covalent, coordinate covalent and hydrogen bonds
(d) Covalent and coordinate covalent Q12. Which one of the following mixtures is homogeneous?
(a) Starch and sugar
(b) Methanol and water
(c) Graphite and charcoal
(d) Calcium carbonate and calcium bicarbonate
1. (d)2. (c)3. 4. (b)5. 6. (d)7. (d)8. (b)9. (d)10. (d)11. (c)12. (b)