# (Paper) BSNL Telecom Technical Assistant (TTA) 2008 Model Question Papers (2)

**Paper : BSNL Telecom Technical Assistant
(TTA) 2008 Model Question Papers**

*Page - 2*

51.The energy equivalent to 1 a.m.u. is

a) 931 MeV b) 931 eV c) 931 KeV d) 9.31 MeV

52.The ratio of kinetic energy and total energy of an electron in a Bohr orbit is

a) + 2 b) – 1 c) + 1 d) – 2

53.The size of an atom is of the order of

a) 1 Å b) 1 fermi c) 1 nm b) 1 micron

54.The mass defect per nucleon is called

a) Packing fraction b) Binding Energy

c) Ionization Energy d) Excitation Energy

55.Nuclear Binding Energy is equal to

a) Mass of Nucleus b) Mass defect of Nucleus

c) Mass of Proton d) Mass of Neutron

56.The Pfund series of Hydrogen spectrum lies in the region\

a) Infrared b) Visible c) Ultraviolet d) X-Ray

57.The number of neutrons in 92U238 is

a) 92 b) 238 c) 330 d) 146

58.The energy required to remove an electron in a hydrogen atom from n = 10 state is

a) 136.0 eV b) 13.60 eV c) 1.36 eV d) 0.136 eV

59.The angular momentum of electron in nth orbit is given by

a) b) c) d)

60.The rest energy of an electron is

a) 510 MeV b) 51 MeV c) 931 MeV d) 93.1 MeV

61.In the lowest energy level of hydrogen atom, the electron has the angular momentum

a) ?/h b) h/? c) h/2? d) 2?/h

62.Laser is working in the principle of

a) Stimulated emission of radiation b) Spontaneous emission of radiation

c) Population inversion d) Normal population

63.The output beam of Ruby Laser has the wavelength of

a) 6943 Å b) 6328 Å c) 6300 Å d) 5500 Å

64.In the He-Ne Laser , the He-Ne in the mixture of

a) 10:1 b) 2:1 c) 4:1 d) 5:1

65.The full form of LIDAR is

a) Light Amplitude and Ranging

b) Light Detection and Ranging

c) Light Defect and Ranging

d) Laser Detection and Ranging

66.Which one of the following is solid state laser?

a) Nd:YAG Laser b) He-Ne Laser c) CO2 Laser d) GaAs Laser

67.Populaton Inversion is achieved by means of

a) Optical pumping b) Gas pumping

c) Mechanical pumping d) Solid pumping

68.GRASERS are

a) Galium Arsenide Lasers b) Gamma Ray Lasers

c) General Ranging Lasers d) Gallium Radium Lasers

69.LASER Beam is

a) Highly monochromatic b) Highly Intense

c) Highly Coherent d) All of the above

70.Which one of the following cannot be used as a pulsed device?

a) CFA b) BWO c) TWT d) Magnetron

71.Klystron works in the principle of

a) Velocity Modulation b) Amplitude Modulation

c) Frequency Modulation d) Phase Modulation

72.Strapping in Magnetron is used to

a) prevent mode jumping b) ensure bunching

c) improve the phase focusing effect d) prevent cathode back heating

73.Which is not a TWT slow wave structure

a) Coupled cavity b) helix c) ring bars d) periodic permanent magnet

74.30 to 300 MHz frequency range is categorized as

a) MF b) VHF c) UHF d) SHF

75.Find the centre of the circle whose two extremities of diameter are (2,3) & (4,-1) is

a) (3,1) b) (6,8) c) (3,-2) d) (-6,8)

76.The centre and radius of the circle x2+y2+4x–6y+2=0 are

a) (-2,3) & 5 b) (-2,3) & 5 c) (2,-3) & 5 d) (2,-3) & 2

77.The angle between the straight lines x + 2y -3 = 0 & 2x + 4y -4 = 0 is

a) ? = 90º b) ? = 60º c) ? = 0º d) ? = 45º

78.The condition for the pair of straight lines ax2+2xy+by2+2x+2y+3=0 to be perpendicular is

a) h2–ab = 0 b) ab = 2 c) a+b = 0 d) a-b = 0

79.The particular integral of +3 + 2y = 2e-x is

a) 2xe-x b) 2e-x c) x2e-x d) xe-x

80.The particular integral of +4 + 4y = 3sin2x is

a) - cos2x b) cos2x c) sin2x d) 3xcos2x

81.The complementary function of (D2+3)y = e-x is

a) Ae x + Be x b) (A+Bx) e x

c) A cos3x + B sin3x d) A cos x + B sin x

82.The solution of (D2-2D-15)y = 0 is

a) y = Ae3x + Be5x b) y = Ae-3x + Be-5x

c) y = Ae5x + Be-3x d) y = Ae-5x + Be3x

83.The particular integral of + y = 3 is

a) 3 b) x/3 c) 3/y d) -3

84.The area bounded by x2 = 2y, the x-axis and the lines x = 1 and x = 3 is

a) b) c) d)

85.The area of the curve y = sin x bounded by the x-axis from x = 0 to x = 2? is

a) 0.5 b) 1.0 c) 1.5 d) 2.0

86.The area enclosed by the curve xy = 8 and x-axis from x = 1 to x = 4 is

a) 8 log 2 b) 16 log 2 c) 4 log 2 d) 2 log 4

87.The area bounded by the curve x = 3y2 – 9 and the lines x = 0, y = 0 and y = 1 is

a) 8 b) c) d) 3

88.When the area enclosed by the curve y = and the x-axis from x = 0 and x = 4 is rotated about the x-axis, the volume generated is

a) b) c) d)

89.The area included between the curve y = x – x2 and the x-axis revolves about the x-axis. The volume generated by the area is

a) b) c) d)

90.If the area enclosed between the curve y2 = x3 + 5x and the x-axis from x = 2 to x = 4 is revolved about the x-axis, the volume of the solid generated is

a) 45? b) 90? c) 120? d) 60?

91.

a) 12 b) 0 c) 6 d) 18

92. =

a) sin-1x b) cos-1x c) tan-1x c) cot-1x

93.

a) log f(x) b) 2 c) f(x) d) f(x)/2

94.

a) sec x b) tan x c) cos x d) cot x

95.The acceleration of a particle at any time t is given by 3×2 – 2x + 1, then the velocity of the particle at any time is

a) x3 -2x 2 + x b) x3 -x 2 + x c) x 2 + x d) x 2 + x +1

96.The Laplace transform of f(t) = t2 e-3t is

a) b) c) d)

97.The Laplace transform of f(t) = 1 + cos2t is

a) b) c) d)

98.The Laplace transform of unit step function is

a) b) c) 1 d)

99.The initial value of the function F(S) =

a) 1 b) 0 c) 2 d)

100.The inverse Laplace transform of is

a) e-t b) 1-e-t c) 1- et d) 2(1+ e-t)

101.The inverse Laplace transform of is

a) et cos2t b) et sin2t c) e-t cos2t d) e-t sin2t

102.(1+i)3 is equal to

a) 3 + 3i b) 1 + 3i c) 3 – 3i d) 2i – 2

103.The value of i13+i14+i15+i16 is

a) 0 b) -1 c) i d) –i

104. The polar form of complex number -1- i is

a) 2(cos + i sin ) b) 2(cos + i sin )

b) 2(cos - i sin ) d) 2(cos + i sin )

105.The modulus of a complex number is

a) b) 2 c) 1 d)

106.The value of (3+?+3?2)4 is

a) 16 b) 16 ? c) -16 ? d) 0

107.The value of is

a) cos 2? + i sin 2? b) cos ? + i sin ?

c) cos ? - i sin ? d) cos 26? + i sin 26?

108.The value of the fourier coefficient bn for the function f(x) = cosx defined in (-?, ?) is

a) 0 b) 1 c) ? d) -2 ?

109. The value of the fourier coefficient a0 for the half range series for f(x) defined in (0, ?) is

a) a0 = b) a0 =

c) a0 = d) 0

110.The value of the fourier coefficient an for the function f(x) is odd is

a) 0 b) an =

c) an= d) a0 =

111.The value of the fourier coefficient bn for the function f(x) is even is

a) 0 b) bn =

c) bn = d) bn =

112.If u = exy then x

a) u b) u logeu c) logeu d) ueu

113.If u = then the value of is

a) b) 0 c) x+y d) -1

114.If u = sin-1 , then the value of is

a) b) c) d)

115.If u = xy, then is

a) y/x b) xyx-1 c) yxy-1 d) xy-1

116. Given = = 6 and . = 18, the angle between and is

a) b) c) d)

117.( - ) x ( + ) =

a) 2 x b) x c) 2 x d) 2 - 2

118.The volume of the parallelepiped whose three coterminous edges are represented by the vectors + , + , + is

a) 2 b) 3 c) 4 d) 1

119.The value of p such that the vectors -2 + 3 , 4 +3 - and 11 +p + 7 are coplanar is

a) -7 b) 0 c) -12 d) 12

120.Reverberation of sound means

a) existence of sound in a room

b) vibration of sound waves

c) existence of sound eventhough the source of sound is cutoff

d) strong echoes

121.Ultrasonic waves can be produced by

a) Piezo-electric effect b) Inverse Piezo-electric effect

c) Magnetostriction effect d) Both b & c

122.The Sabine’s formula for reverberation time is

a) T = b) T =

c) T = d) T = 0.16 aAS