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Physics M.C.Q (1 Marks)

Communication · MP Board (MPBSE) STD 12 Science (Madhya Pradesh - English Medium). 71 questions.

Questions · Page 2 of 2

M.C.Q (1 Marks)

MCQ 511 Mark
A laser beam is used for carrying out surgery because it
  • A
     Is highly monochromatic
  • B
     Is highly coherent
  • C
    Is highly directional
  • ✓
    Can be sharply focussed
Answer
Correct option: D.
Can be sharply focussed
 Can be sharply focussed
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MCQ 521 Mark
The maximum distance upto which $TV$ transmission from a $TV$ tower of height $h$ can be received is proportional to
  • ✓
    $ \mathrm{h}^{1 / 2} $
  • B
    $ \mathrm{~h} $
  • C
    $ \mathrm{~h}^{3 / 2} $
  • D
    $ \mathrm{~h}^2$
Answer
Correct option: A.
$ \mathrm{h}^{1 / 2} $
$ \mathrm{h}^{1 / 2} $
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MCQ 531 Mark
The attenuation in optical fibre is mainly due to
  • A
     Absorption
  • B
     Scattering
  • C
     Neither absorption nor scattering
  • ✓
     Both (a) and (b)
Answer
Correct option: D.
 Both (a) and (b)
 Both (a) and (b)
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MCQ 541 Mark
The electromagnetic waves of frequency 2 MHz to 30 MHz are
  • A
    In ground wave propagation
  • ✓
     In sky wave propagation
  • C
     In microwave propagation
  • D
     In satellite communication
Answer
Correct option: B.
 In sky wave propagation
 In sky wave propagation
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MCQ 551 Mark
Maximum useable frequency (MUF) in F-region layer is x, when the critical frequency is 60 MHz and the angle of incidence is 70°. Then x is
  • A
     150 MHz
  • B
     170 MHz
  • ✓
     175 MHz
  • D
     190 MHz
Answer
Correct option: C.
 175 MHz
 175 MHz
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MCQ 561 Mark
An antenna behaves as resonant circuit only when its length is
  • A
     $\frac{\lambda}{2}$
  • B
     $\frac{\lambda}{4}$
  • C
     $\lambda$
  • ✓
    $\frac{\lambda}{2}$ or integral multiple of $\frac{\lambda}{2}$
Answer
Correct option: D.
$\frac{\lambda}{2}$ or integral multiple of $\frac{\lambda}{2}$
$\frac{\lambda}{2}$ or integral multiple of $\frac{\lambda}{2}$
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MCQ 571 Mark
Broadcasting antennas are generally
  • A
    Omnidirectional type
  • ✓
     Vertical type
  • C
     Horizontal type
  • D
     None of these
Answer
Correct option: B.
 Vertical type
Vertical type
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MCQ 581 Mark
The carrier frequency generated by a tank circuit containing 1 nF capacitor and 10 mH inductor is
  • A
     1592 Hz
  • B
     1592 MHz
  • ✓
     1592 kHz
  • D
     159.2 Hz
Answer
Correct option: C.
 1592 kHz
1592 kHz
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MCQ 591 Mark
A laser beam of pulse power $10^{12}$ watt is focussed on an object are $10^{-4} \mathrm{~cm}^2$. The energy flux in watt/ $\mathrm{cm}^2$ at the point of focus is
  • A
    $ 10^{20} $
  • ✓
    $ 10^{16} $
  • C
    $ 10^8 $
  • D
    $ 10^4$
Answer
Correct option: B.
$ 10^{16} $
$ 10^{16} $
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MCQ 601 Mark
Through which mode of propagation, the radio waves can be sent from one place to another
  • A
     Ground wave propagation
  • B
    Sky wave propagation
  • C
     Space wave propagation
  • ✓
     All of them
Answer
Correct option: D.
 All of them
 All of them
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MCQ 611 Mark
If $m_1$ and $m_2$ are the refractive indices of the materials of core and cladding of an optical fibre, then the loss of light due to its leakage can be minimised by having
  • ✓
    $ m_1 > m_2 $
  • B
    $ m_1 < m_2 $
  • C
    $ m_1=m_2$
  • D
    None of these
Answer
Correct option: A.
$ m_1 > m_2 $
$ m_1 > m_2 $
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MCQ 621 Mark
In which frequency range, space waves are normally propagated
  • A
     HF
  • B
    VHF
  • ✓
     UHF
  • D
     SHF
Answer
Correct option: C.
 UHF
UHF
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MCQ 631 Mark
The characteristic impedance of a coaxial cable is of the order of
  • A
     50 W
  • B
     200 W
  • ✓
     270 W
  • D
     None of these
Answer
Correct option: C.
 270 W
270 W
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MCQ 641 Mark
A step index fibre has a relative refractive index of 0.88%. What is the critical angle at the corecladding interface
  • A
     60°
  • B
     75°
  • C
     45°
  • ✓
     None of these
Answer
Correct option: D.
 None of these
None of these
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MCQ 651 Mark
Long distance short-wave radio broadcasting uses
  • A
    Ground wave
  • B
    Ionospheric wave
  • ✓
    Direct wave
  • D
    Sky wave
Answer
Correct option: C.
Direct wave
Direct wave
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MCQ 661 Mark
The process of superimposing signal frequency (i.e. audio wave) on the carrier wave is known as
  • A
    Transmission
  • B
     Reception
  • ✓
     Modulation
  • D
     Detection
Answer
Correct option: C.
 Modulation
Modulation
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MCQ 671 Mark
In short wave communication waves of which of the following frequencies will be reflected back by the ionospheric layer, having electron density $10^{11}\text{ per m}^3$
  • ✓
    $2 MHz$
  • B
    $10 MHz$
  • C
    $12 MHz$
  • D
    $18 MHz$
Answer
Correct option: A.
$2 MHz$
$2 MHz$
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MCQ 681 Mark
In an amplitude modulated wave for audio frequency of 500 cycle/second, the appropriate carrier frequency will be
  • A
     50 cycles/sec
  • B
    100 cycles/sec
  • C
    500 cycles/sec
  • ✓
    50,000 cycles/sec
Answer
Correct option: D.
50,000 cycles/sec
50,000 cycles/sec
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MCQ 691 Mark
AM is used for broadcasting because
  • A
     It is more noise immune than other modulation systems
  • B
     It requires less transmitting power compared with other systems
  • ✓
     Its use avoids receiver complexity
  • D
     No other modulation system can provide the necessary bandwidth faithful transmission
Answer
Correct option: C.
 Its use avoids receiver complexity
 Its use avoids receiver complexity
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MCQ 701 Mark
Range of frequencies allotted for commercial FM radio broadcast is
  • ✓
     88 to 108 MHz
  • B
     88 to 108 kHz
  • C
    8 to 88 MHz
  • D
     88 to 108 GHz
Answer
Correct option: A.
 88 to 108 MHz
88 to 108 MHz
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MCQ 711 Mark
The velocity factor of a transmission line x. If dielectric constant of the medium is 2.6, the value of x is
  • A
     0.26
  • ✓
     0.62
  • C
     2.6
  • D
     6.2
Answer
Correct option: B.
 0.62
 0.62
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M.C.Q (1 Marks) - Page 2 - Physics STD 12 Science Questions - Vidyadip