### CHAPTER 7:Oscillations

The time required to complete one vibration is called
(a)  time period         (b)               frequency
(c)  time period          (d)    velocity

(2)        The force which opposes the applied force producing the displacement in the spring is called                                    (a)  restorign force    (b)     periodic force
(c)  centripetal force  (d)     resistive force

(3)        The number of vibrations completed by a body in one second is called
(a)  time period         (b)     frequency
(c)  total vibrations    (d)     displacement

(4)        The distance of vibrating body at any instant from its equilibrium position is called                                                                                                                                                    (a)   displacement     (b)  frequency     (c)  amplitude                     (d)   time period

(5)        For a body executing S.H.M, its
(a)  momentum remains constant
(b)  potential energy remains constant
(c)  kinetic energy remains constant
(d)  total energy remains constant

(6)        Which of the following does not exhibit S.H.M?
(a)  a plucked violin string
(b)  a mass attached to a spring
(c)  a train shunting between two terminals
(d)  a simple pendulum

(5)               If the displacement of a body executing S.H.M is plotted against time, then the curve is known
(a)  frequency of S.H.M
(b)  period of S.H.M
(c)  wave form
(d)  none of them

(8)        The wave from of S.H.M will be
(a)  square wave       (b)  sine wave
(c)  rectified wave     (d)  saw tooth wave

(1)               An object undergoes S.H.M has maximum speed when its displacement from the mean position is
(a)  maximum speed
(b)  zero
(c)  half of the maximum value
(d)  one third of the maximum value

(10)      An object undergoes S.H.M has maximum acceleration when its displacement form the mean position is
(a)  maximum
(b)  zero
(c)  half of the maximum value
(d)  one third of the maximum value

(11)      In vibratory motion.
(a)    P.E remains constant
(b)    K.E remain constant
(c)    Total energy remain constant
(d)    Total momentum remain constant

(12)      The waveform of S.H.M is.
(a)  standing wave
(b)  sine wave
(c)  square wave
(d)  none

(13)      S.I unit of frequency is.
(a)  vibration s-2
(c)  hetz
(d)  ms-1

(15)      In S.H.M the velocity of a particle is maximum at
(a)  mean position
(b)  extreme position
(c)  Middle between mean and extreme position on the right side.
(d)  Middle between mean and extreme position on the left side.

(16)      The acceleration  of a projection on the diameter for a particle moving along a circle is.
(a)  w2x
(b)  wx2
(c)  –w2x
(d)  –wx2

(17)      Total energy of a body executing S.H.M, is directly proportional to.
(a)  square root of amplitude
(b)  the amplitude
(c)  reciprocal of amplitude
(d)  square of amplitude

(18)      The time period of a second pendulum is-
(a)  4 seconds
(b)  3 seconds
(c)  2 seconds
(d)  6 seconds

(19)      The length of second pendulum is.
(a)  100 cm
(b)  99 cm
(c)  99.2 cm
(d)  98 cm

(20)      If length of second pendulum becomes four times, then its time period will become.
(a)  four time
(b)  six times
(c)  eight time
(d)  two times

(21)      The force responsible for the vibratory motion of the simple pendulum.
(a)  mg cosθ
(b)  mg sinθ
(c)  mg tanθ
(d)  mg

(22)      The frequency of the second pendulum is.
(a)  1 hertz
(b)  0.5 hertz
(c)  1.5 hertz
(d)  2.5 hertz

(23)      Simple harmonic motion is a type of .
(a)  Rotational motion
(b)  Circular motion
(c)  Musical arrangement
(d)  Vibratory motion

(24)      The SI unit of force constant is identical with that of.
(a)  Force
(b)  Pressure
(c)  Surface tension
(d)  Loudness

(25)      When the amplitude of a wave become double, its energy become.
(a)  Double
(b)  Four times
(c)  One half
(d)  None time

(26)      A simple pendulum suspended form the ceiling of a lift has time period T, when the lift is at rest. When the lift falls freely, the time period is.
(a)  Infinite
(b)  T/g
(c)  Zero
(d)  g/T

(27)      The energy of S.H.M is maximum at.
(a)  Mean position
(b)  Extreme position
(c)  In between mean position
(d)  All positions during SHM

(28)      The product of frequency and time period is equal to.
(a)  1
(b)  2
(c)  3
(d)  4

(29)         The displacement of SHM is written as X = Xo sinωt , If
displacement is written by X = Xo cosωt then phase constant will be equal to.
(a)  0o
(b)  45 o
(c)  90 o
(d)  180 o

(30)         For what displacement the P.E becomes ¼ of its maximum value?
(a)  x = xo
(b)  x = xo/2
(c)  x = xo/4
(d)  x = xo2/2

(31)        Sharpness of resonance is.
(a)    directly proportional to damping force
(b)   inversely proportional to damping force
(c)    equal to square of damping force
(d)   equal to square of damping force

(32)      Which one does not work according to resonance?
(a)     T.V
(c)     Microwave oven
(d)    Bulb

(33)      The restoring force acting on simple pendulum is given by.
(a)     mg sin θ
(b)    –mg sin θ
(c)     ms cos θ
(d)    –mg cos θ

(34)      Phase of SHM describes.
(a)  Displacement only
(b)  Direction of motion only
(c)  Both displacement and direction of motion
(d)  Neither displacement nor direction of motion

(35)      Natural frequency of simple pendulum depends upon.
(a)  Its mass
(b)  Its length
(c)  Square of its length
(d)  Square root of its length

(36)      Electrical resonance is observed in.
(b)  Microwave oven
(c)  Both in radio and microwave oven
(d)  Neither in radio nor in microwave oven

(37)      Total distance traveled by bob of simple pendulum in one vibration is equal to.
(a)  Amplitude
(b)  Square of amplitude
(c)  2 x amplitude
(d)  4 x amplitude

(38)      When K.E energy of SHM is maximum, its.
(a)  P.E is zero
(b)  Acceleration is zero
(c)  Restoring force is zero
(d)  All P.E acceleration & restoring force are zero

(39)      In damped harmonic oscillation, which one deceases?
(a)  Amplitude of vibration
(b)  Energy of vibration
(c)  Both amplitude and energy
(d)  Neither amplitude nor energy

(40)      Forced vibration are known as
(a)  Simple harmonic vibration
(b)  Natural vibration
(c)  Driven harmonic vibration
(d)  Free vibration

### COMMON COLLECTOR CONFIGURATION OF A TRANSISTOR

COMMON COLLECTOR CONNECTION

In  this  configuration  the  input  is  applied  between the  base  and  the  collector and  the  output  is  taken  from  the  collector  and  the  emitter.  Here  the  collector  is common to both the input and the output circuits as shown in Fig.

Common Collector Transistor Circuit

In  common  collector  configuration  the  input  current  is  the  base current  IB  and  the output current is the emitter current IE. The ratio of change in emitter current to the  change in the base current is called current amplification factor.

It is represented by

COMMON COLLECTOR CIRCUIT

A test  circuit  for determining the  static characteristic  of an NPN transistor is shown in Fig. In this circuit the collector is common to both the input and the output circuits.   To   measure   the   base   and   the   emitter   currents,   milli   ammeters   are connected in series with the base and the emitter circuits. Voltmeters are connected   across the input an…