SCIENCE
36.
Which of the following materials has the
maximum density ?
(1) iron
(2) lead
(3) gold
(4) platinum
37. The length of the seconds needle of
a watch is 1 cm. The displacement of its
tip in 15 seconds is :
(1)1 cm
(2)2 cm
(3)root2 cm
(4)2 root2 cm
38. A glass rod is rubbed with silk. During
this process, the mass of the glass rod
:
(1) decreases bv a very small amount
(2) increases by a very small amount
(3) does not change
(4) increases appreciably
39. The characteristic of sound which
helps us to distinguish the sounds roduced
by two musical instruments is :
(1)loudncss
(2)wavelength
(3)pitch
(4)timbre
40. Speed of lifiht in vacuum is 3xl08
m/s. A laser signal sent from the earth
towards the moon returns to the earth
after 2.57 seconds. The distance of the
moon from the earth is :
(1)3.86 X
10 raise to 6 m
(2)3.86 X 10 raise to 8 m
(3)7.72 X 10 raise to 8 m
(4)7.72 X 10 raise to 6 m
41. The specific heat capacity of copper
is 3 times that of lead. If the thermal
capacity of 10 kg of lead is equal to
the thermal capacity of m kg of copper,
then m is equal to :
1)10/3 kg
(2)3/10 kg
(3)30 kg
(4) 1/30 kg
42. The focal length of a concave lens
is 50 cm. The power of the lens is :
(1)+2 D
(2)-2 D
(3)+ 50 D
(4)- 50 0
43. Two
identical charged metal spheres are kept
on two insulating stands. One sphere contains
+2 coulomb of charge and the other —4
coulomb of charge. They are brought in
to contact and again separated and kept
on the insulating stands. Each sphere
now contains a charge equal to :
(1) +2 coulomb
(2)—4 coulomb
(3) —2 coulomb
(4)—1 coulomb
44. The working principle involved in
an optical fibre is:
(1) total internal reflection
(2) refraction
(3) reflection
(4) dispersion
45.
Within a chemical cell, electric charge
is transferred bv the motion of :
(1) free electrons
(2) positive ions
(3) negative ions
(4) both positive and negative ions
46. The length and area of cross-section
of a conductor are doubled. The resistance
of the conductor is :
(1) doubled
(2) halved
(3) unchanged
(4) made one-fourth
47. Sonar is a :
(1) bright star
(2) comet
(3) space-ship
(4) instrument to measure the depth of
sea using ultrasonic waves
48. Colourless gas with a pungent smell
which turns lime water milky is :
(1) CO
2
(2) so
2
(3)Cl 2
(4)NO 2
49. Metal
used for galvanizing iron is :
(I)Zn
(2)Cu
(3)Sn
(4)Mg
50.The gas
which will not produce 'Green House Effect':
1)CO2
(2)N2O
(3)N2
(4)CH4
51. An atom
has 8p, 8e and 9n. It can be represented
as :
(1)9O8
(2)17F9
(3)17O9
(4)17O8
52. Vinegar is a dilute solution of an
acid. The acid is :
(1) Acetic acid
(2) Sulphuric acid
(3) Citric acid
(4) Tartaric acid
53. Substance which causes temporary hardness
to water :
(1) NaHC03
(2) Na2CO3
(3) CaCO3
(4) Mg (HCO3)2
54. 'Dry ice' is :
(1) solid CO2
(2) s?olid H2O
(3) solid SO2
(4) solid H2O2
55, The gas' which directly combines with
F2 ls :
(1)O2
(2)N2
(3)Ar
(4)Xe
56. Which of the following is an acidic
salt ?
(1) Na2CO3
(2) NaHS04
(3) NaN03
(4) Na2HP03
57. The atom with 3 electrons in the outer
most shell is:
1) N
(2) Al
(3)Mg
(4)S
58. Which
of the following is a Metalloid ?
(1) Pb
(2)Mg
(3)As
4)Bi
59. Hardest
element is
(1)C
(2)W
(3)Au
(4)Cr
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