Q.1:- Which one of the following phenomena cannot attributed to the refraction of light ?
- Twinkling of stars
Q.2:- Optical fibre works on the principle of ?
- Total internal reflection
Q.3:- Which of the following produce a virtual image longer in size than the object ?
- Concave lens
- Convex lens
- Concave mirror
- (b) and (c) both
Q.4:- A man inside an artificial satellite feels weightlessness because the force of attraction due to earth is ?
- Zero at that earth is
- Is balanced by the force of attraction due to moon
- Equal to centripetal force
- Non-effective due to particular design of the satellite
Q.5:- Camberts, law is related to ?
Q.6:- What is viewed through an electron microscope ?
- Electrons and other elementary particles
- Structure of bacteria and viruses
- Inside of human stomach
- Inside of the human eye
Q.7:- To an observer on the lunar surface, during the day time the sky will appear to be ?
- Light yellow
Q.8:- Why is red light employed for danger signals ?
- Red colour is soothing to the eye
- Human eye is most sensitive to red colour
- Red light is scattered least
- Red light is scattered most
Q.9:- Blue colour of sky is consequence of ?
Q.10:- Unit of solid angle is ?
Q.11:- Who invented the Safety Razor ?
- Steve Cher
- Lar Strauss
- Steve Job
Q.12:- When the velocity of a body is doubled ?
- Its P.E. is doubled
- Its acceleration is doubled
- Its K.E. is doubled
- Its momentum is doubled
Q.13:- The distance between two crests in a wave in given by ?
- Wave number
- Wave velocity
Q.14:- Roadways are banked on curves so that
- The speeding vehicles may not fall inwards
- The frictional force between the road and vehicle may be decreased
- The wear and tear of tyre may be avoided
- The weight of the vehicle may be decreased
Q.15:- It a body moves with a constant speed in a circle ?
- No work is done on it
- No force acts on it
- No acceleration is produced in it
- Its velocity remains constant
Q.16:- Fat can be separated from milk in a cream separator because of ?
- Cohesive force
- Gravitational force
- Centripetal force
- Centrifugal force
Q.17:- A small drop falls from rest from a large height h in air. The final velocity is ?
- Almost independent of h
- Propotional to h
- Inversely proportional to h
- Proportional to ….h
Q.18:- Insects can move on the surface of water without sinking due to ?
- Dynamic lift
- Viscosity of water
- Surface tension of water
- None of these
Q.19:- The reciprocal of specific resistance is ?
- Conductive resistance
- Specific conductance
- Plate resistance
Q.20:- Electromotive force is most closely related to ?
- Electric field
- Magnetic field
- Potential difference
- Mechanical force
Q.21:- The electric intensity on the surface of a charged conductor is ?
- Directed normally to the surface
- Directed tangentially to the surface
- Directed along 45 degree to the surface
Q.22:- Photocells are used for the
- Reproduction of pictures from the cinema film
- Reproduction of sound from the cinema film
- Automatic switching of street light
- (b) and (c) Both
Q.23:- Energy transferred to a person through gamma rays is measured in units of ?
- None of these
Q.24:- In a Hydel station the motion produced in turbines is due to the ?
- Burning of coal
- Burning of diesel
- Flow of water
- Production of steam
Q.25:- Who invented the battery ?