1)Optical fibre mainly used in communication is based on
a) Less absorption coefficient
b) Less scattering
c) Total internet reflection
2) If there was were no gravity , which of the following will not be there for a fluid ?
c) Archimeds’s upward thrust
d) Surface tension
3) Post office box is a device for measuring resistant based on the principle of
b) Meter bridge
c) Ohm meter
4) The phenomenon of bursting of hydrogen balloon is based on
a) Charle’s law
b) Boyle’s law
c) Henry’s law
d) Bernoulli’s law
5) The image from by an object of a compound microscope is
a) Virtual and enlarged
b) Virtual and diminish
c) Real and diminish
d) Real and enlarged
6) A mirror products magnified erect image of and object. The nature of the mirror is
d) Neither convex nor convene
7) What enables us to write on the black board with chalk?
8) By which one of the following , and old written material which cannot be read easily, can be read ?
a) a- ray
9) Which one of the following has given the centripetal force for a car moving on a road ?
a) Force of breaks
b) The driver of the car
c) Force by the steering wheel
d) Friction due to tyres
10) Which one of the following is correct when a body moving in a circular path with constant speed ?
a) The body has constant acceleration
b) The body has constant retardation
c) The body has variable acceleration
d) The body has constant velocity and variable speed
11) In nuclear reaction which one of the following is conserved ?
a) Atomic number
b) Mass number
c) Atomic number, Mass number and energy
d) None of the above
12) Which one of the following forces lead to separation of the cream from the churned milk?
a) Gravitational force
b) Cohesive force
c) Centripetal force
d) Centrifugal force
13) which one of the following reactions is the main cause of the energy radiation from the sun?
a) Fusion reaction
b) Fission reaction
c) Chemical reaction
d) Diffusion reaction
14) Which one of the following mechanisms used the Pascal’s law?
a) The flight take-off
b) The floating of ship
c) The hydraulic brakes
d) The landing of flight
15) When the matter is cooled to very low temperature, it will from
a) Semi- conductor
16) Which one of the following instruments is used by the submarine sailors to see the objects on the surface ?
17) Who gave the first evidence of Big-bang theory ?
a) Edwin Hubble
b) Stephen Hawking
c) S Chandrasekhar
d) Albert Einstein
18) Which one of the following satellites is used to reflect the radio-signals back to the earth ?
a) Natural satellites
b) Active satellites
c) Passive satellites
d) None of these
19) The common soap used in washing is worked by
a) Reducing the surface tension of water
b) Increasing the surface tension of water
c) Reducing the viscosity of water
d) Increasing the viscosity of water
20) if we move from equator to people , the value of g
c) Remains same
d) First increases then decreases