Showing posts with label Tele-comunication. Show all posts
Showing posts with label Tele-comunication. Show all posts

Monday, May 16, 2011

SSC Model test Physics, Chemistry,Mathematics and Telecommunication For SI And ASI telecom

SSC Model test Physics, Chemistry,Mathematics and Telecommunication For SI And ASI telecom
A Practice paper For SI telecom and ASI telecom Consisting of
60 Questions on Physics, Chemistry,Mathematics and Telecommunication
1. Choose the wrong statement.
(a) l kg wt=9.8N
(b) Momentum is a vector quantity
(c) Force is always conserved
(d) Momentum is conserved in the absence of an external force
Ans. (b)
2. If a rock is brought from the surface of the moon
(a) its mass will change
(b) its weight will change, but not mass
(c) both mass and weight will change
(d) its mass and weight will remain the same
Ans. (b)
3. The weight of a body would not be zero
(a) at the centre of the earth
(b) during a free fall
(c) in interplanetary space
(d) on a frictionless surface
Ans. (d)
4. A man is standing on a boat in still water. If he walks towards the shore the boat will
(a) move away from the shore
(b) remain stationary
(c) move towards the shore
(d) sink
Ans. (a)
5. A driver accelerates his car first at the rate of 1.8 m/s2 and then at the rate of 1.2 m/s2. The ratio of the forces exerted by the engines will be respectively equal to
(a) 2:3
(b) 1:2
(c) 2:1
(d) 3:2
Ans. (d)
6. During a planned manoeuvre in a space flight, a free-floating astronaut A pushes another free- floating astronaut B, the mass of A being greater than that of B. Then, the magnitude of the force exerted by astronaut A on astronaut B is
(a) equal to zero
(b) equal to the force exerted by B on A
(c) greater than the force exerted by B on A
(d) less than the force exerted by B on A
Ans. (b)
7. In the above problem, during a push
(a) the acceleration of A is greater than that of B
(b) the acceleration of A is less than that of B
(c) neither is accelerated
(d) their accelerations are equal in magnitude but opposite in direction
Ans. (b)
8. The force needed to produce an acceleration of 6 m/s2 in a ball of mass 4 kg will be
(a) 24N
(b) 30N
(c) 32N
(d) 36N
Ans. (a)
9. The SI unit of density is
(a) kg m-3
(b) g cm-3
(c) kg wt cm-2
(d) none of these
Ans. (a)
10. Two spheres of the same size are made of the same metal, but one is hollow
and the other is solid. They are heated to the same temperature. Then,
(a) the hollow sphere will expand more
(b) the solid sphere will expand more
(c) both spheres will expand almost equally
(d) only the solid sphere will expand
Ans. (c)
11. When an inflated type bursts, the air escaping out
(a) will get heated up
(b) will be cooled
(c) will not undergo any change in its temperature
(d) will be liquefied
Ans. (b)
12. When the momentum of a body increases by 10%. its K.E. increases by
(a) 20%
(b) 40%
(c) 44%
(d) none of these
Ans. (d)
13. Watt sec represents the unit for
(a) energy
(b) power
(c) force
(d) none of these
Ans. (a)
14. The atomic number of an element is determined by
(a) The number of electrons in one atom
(b) The number of neutrons in one atom
(c) The valency of the element
(d) The number of protons in one atom
Ans. (a)
15. The value of e/m of an electron was measured by:
(a) Millikan
(c) Dalton
(b) J.J. Thomson
(d) Rutherford
Ans. (a)
16. Which of the following is not a noble gas?
(a) Helium
(b) Xenon
(c) Radium
(d) Radon
Ans. (c)
17. Which of the following properties generally decrease along a period?
(a) Ionization energy
(b) Electron affinity
(c) Metallic character
(d) Valency
Ans. (c)
18. The elements in the middle of the periodic table are called
(a) Metalloids
(b) Transition elements
(c) Rare earth element
(d) Noble gases
Ans. (b)
19. The fractional distillation of coal tar yields
(a) Carbon disulphide
(b) carbon tetrachloride
(c) Kerosene oil
(d) Benzene
Ans. (d)
20. The formula of ethyne is
(a) C2H2
(b) C6H6
(c) C2H4
(d) C2H6
Ans. (a)
21. Water gas consists of
(a) Water vapour and coal dust
(b) a mixture of carbon monoxide and hydrogen
(c) a mixture of carbon monoxide and nitrogen
(d) Water vapour and methane
Ans. (b)
22. The reaction of one mol of bromine with ethyne yields
(a) BrCH2—CH2Br
(b) BrCH = CHBr
(c) Br2CH—CHBr2
(d) CH3—CH2Br
Ans. (b)
23. The main constituent of LPG is
(a) Methane
(b) Ethane
(c) Propane
(d) Butane
Ans. (d)
24. The general formula to represent alkenes is
(a) CnH2n+1
(b) CnH2n
(c) CnH2n+2
(d) CnH2n-2
Ans. (c)
25. Molecular mass of Butane is
(a) 54
(b) 56
(c) 58
(d) 60
Ans. (c)
26. Which of the following ions is furnished by acids in aqueous solution?
(a) OH- ions
(b) H+ ions
(c) H3O+ ions
(d) None of these
Ans. (b)
27. Which of the following is not an organic acid?
(a) Tartaric acid
(b) Oxalic acid
(c) Ascorbic acid
(d) Nitric acid
Ans. (d)
28. Acids turn blue litmus
(a) Green
(b) Red
(c) Yellow
(d) orange
Ans. (b)
29. Acidity of aluminum hydroxide is
(a) l
(b) 2
(c) 4
(d) 3
Ans. (d)
30. pH of tomato juice is 4, that means it is
(a) basic
(b) acidic
(c) neutral
(d) none of these
Ans. (b)
31. A man loses 12% of his money and after spending 70% of the remainder, he was left
with Rs 210. The money that he had at the beginning is
(a) Rs 810
(b)Rs 800
(c) Rs 790
(d) Rs 780
Ans. (b)
32. The salaries of A, B and C together amount to Rs 333, if they spend 80%, 85% and
75% of their respective salaries. If their savings are 7 : 6 : 9, then their respective
salaries are
(a) Rs 102, Rs 118, Rs 113
(b) Rs 105, Rs 120, Rs 108
(c) Rs 85, Rs 125, Rs 123
(d)  none of these
Ans. (b)
33. In an examination, 34% of the candidates fail in Arithmetic and 42% in English. If
20% fail in Arithmetic and English, the percentage of those passing in both subjects is
(a) 44
(b) 45
(c) 46
(d) 47
Ans. (a)
34. A person purchases 20 litres of juice at Rs 2.20 per litre and diluted it with water to
make the contents 22 litres. In order to earn 10 % profit he should sell the juice at
(a) Rs 2.20
(b) Rs 2.00
(c) Rs 2.35
(d) Rs 2.40
Ans. (a)
35. A man deposited Rs 8,000 in a bank for 3 years at 5% per annum compound interest.
After 3 years he will get
(a) Rs 8,800
(b) Rs 9,000
(c) Rs 9,200
(d) Rs 9,261
Ans. (d)
36. A person walks from his house at a speed of 4 km/hr and reaches his school 5 minutes
late. If his speed has been 5 km/hr, he would have reached 10 minutes earlier. The
distance of the school from his house is
(a) 5km
(b) 6km
(c) 7km
(d) 8km
Ans. (a)
37. A sum of money at compound interest becomes double of itself in 15 yrs. The rate of
interest is
(a) 5.1%
(b) 5%
(c) 4.7%
(d) 4.8%
Ans. (c)
38. A man sells two horses at0the same price. On one he makes a profit of 10% and on
the other he suffers a loss of 10%. On the whole he
(a) makes no profit no loss
(b) makes a profit of 1%
(c) suffers a loss of 1%
(d) suffers a loss of 2%
Ans. (c)
39. 3 men can do as much work as 5 women 10 children. If 40 children can finish
work in 7 days, then 6 men, 5 women and 5 children will finish the same work in
(a) 8 days
(b) 9 days
(c) 10 days
(d) none
Ans. (a)
40.  90 km per hour is same as
(a) 50 m/sec
(b) 25 m/sec
(c) 25 m/min
(d) 50 m/min
Ans. (b)
41. The solution of the differential equation
d2y/dx2 – 2dy/dx + y = 0 is -
(a) y = (c1 + c2x)ex
(b) y = c1ex
(c) y = x e x
(d) None of these
Ans. (a)
42. The number of non-empty subsets of the set
{1, 2, 3, 4} is—
(a) 16
(b) 12
(c) 15
(d) 8
Ans. (c)
43. The tangent to the curve x2/a2 + xy2/b2 = 1 at the point (a, 0) -
(a) Makes an angle of 30° with x-axis
(b) Is parallel to x-axis
(c) Makes an angle of 45° with x-axis
(d) Is perpendicular to x-axis
Ans. (d)
44. The expression (sin ø + cos ø) has the maximum value, when ø is equal to—
(a) 30°
(b) 45°
(c) 60°
(d) 90°
Ans. (b)
45. The number log2 7 is—
(a) An integer
(b) A rational number
(c) An irrational number
(d) A prime number
Ans. (c)
46.In frequency modulation, frequency is
a. constant
b. zero
c. variable
47.  In frequency modulation, amplitude is
48.  FSK is
a)      frequency shift keying
b)      frequency shine keying
c)      frequency shine keyboard
d)     none of these
49. The frequency range of 1GHZ to 30GHZ are referred as
a)      sound waves
b)      micro waves
c)      mini waves
d)     none of these
50.  Discrete signal is represented by
a)      coding
b)      modulation
c)      demodulation
d)     sequence of samples
51.In amplitude modulation, frequency is
a)      constant
b)      zero
c)      variable
d)     one
52. Low pass filter attenuates
a)      high frequencies
b)      low frequencies
c)      medium frequencies
d)     none of these
53. Micro wave communication is used in
a)      TNEB
b)      telephone networks
c)      industries
d)     none of these
54. In optical communication, carrier is
a)      electromagnetic waves in optical frequency
b)      electromagnetic waves in maximum frequency
c)      electromagnetic waves in minimum frequency
d)     none of these
55.  Optical fibre is fabricated by
a)      glass
b)      copper
c)      aluminium
d)     none of these
56.which one of the following is  the type of ‘superheterodyning’
a.Radio transmitter
b.TV receiver
57.Primary colours are,,,red.yellow
d.none of these
58. Sound signals in TV are
a)      amplitude modulated
b)      dc modulated
c)      frequency modulated
d)     a and c
59.Communication is a process of
a)      transfer of information
b)      transfer of energy
c)      transfer of channel
d)     none of these
60.  Modulation index is
a)      Vm/Vc
b)      Vc/Vm
c)      Vm/Ic
d)     None of these