NEET Online Exam: Physics Quiz!

48 Questions | By Blogblog1968 | Last updated: Mar 22, 2022 | Total Attempts: 917

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1.

Alternating current can be defined as current that varies in
- A.
  
  Amplitude and direction
- B.
  
  Magnitude and phase
- C.
  
  Amplitude and time
- D.
  
  time and phase
2.

Before a 120-volt dc source can be used to power a 12-volt load, the voltage must be reduced. Which of the following methods can be used?
- A.
  
  A resistor placed in parallel with the load
- B.
  
  A resistor placed in series with the load
- C.
  
  A step-down transformer placed in series with load
- D.
  
  A step-down transformer placed in parallel-with the load
3.

Alternating current has replaced direct current in modern transmission systems because it has which of the following advantages?
- A.
  
  Ac can be transmitted with no line loss
- B.
  
  Ac can be transmitted at higher current levels
- C.
  
  Ac can be transmitted at lower voltage levels
- D.
  
  Ac can be readily stepped up or down
4.

A waveform is a graphic plot of what quantities?
- A.
  
  Current versus time
- B.
  
  Amplitude versus time
- C.
  
  Voltage versus amplitude
- D.
  
  Magnitude versus amplitude
5.

Which of the following properties surrounds a current-carrying conductor?
- A.
  
  A magnetic field
- B.
  
  A repulsive force
- C.
  
  An attractive force
- D.
  
  An electrostatic field
6.

Which of the following statements accurately describes the magnetic field surrounding a current-carrying conductor?
- A.
  
  It is parallel to and equal along all parts of the conductor
- B.
  
  It is parallel to and maximum at the most negative part of the conductor
- C.
  
  It is perpendicular to and equal along all parts of the conductor
- D.
  
  It is perpendicular to the conductor and maximum at the most negative point of the conductor
7.

Which of the following factors determine(s) the intensity of a magnetic field surrounding a coil?
- A.
  
  The amount of current flow through the coil
- B.
  
  The type of core material
- C.
  
  The number of turns in the conductor
- D.
  
  All of the above
8.

When you grasp a coil in your left hand with your thumb pointing in the direction of the north pole, your fingers will be wrapped around the coil in the direction of the
- A.
  
  Voltage potential
- B.
  
  Magnetic field
- C.
  
  Current flow
- D.
  
  South pole
9.

The power consumed in a conductor in realigning the atoms which set up the magnetic field is known as what type of loss?
- A.
  
  Hysteresis loss
- B.
  
  Magnetic loss
- C.
  
  Field loss
- D.
  
  Heat loss
10.

The magnetic field surrounding a straight conductor is (a) what shape, and (b) is in what position relative to the conductor?
- A.
  
  (a) Linked oblong (b) Parallel
- B.
  
  (a) Concentric circles (b) Parallel
- C.
  
  (a) Linked oblong (b) Perpendicular
- D.
  
  (a) Concentric circles (b) Perpendicular
11.

Why is a two-pole magnetic field set up around a coil?
- A.
  
  Because separate lines of magnetic force link and combine their effects
- B.
  
  Because concentric lines of force cross at right angles and combine.
- C.
  
  Because lines of force are separated and bent at the coil ends
- D.
  
  Because separate lines of force are attracted to the two poles of the coi
12.

When a conductor is moving parallel to magnetic lines of force, (a) what relative number of magnetic lines are cut, and (b) what relative value of emf is induced?
- A.
  
  (a) Minimum, (b) maximum
- B.
  
  (a) Minimum, (b) minimum
- C.
  
  (a) Maximum, (b) maximum
- D.
  
  (a) Maximum, (b) minimum
13.

When the induced voltage in a conductor rotating in a magnetic field is plotted against the degrees of rotation, the plot will take what shape?
- A.
  
  A circle
- B.
  
  A sine curve
- C.
  
  A square wave
- D.
  
  A straight line
14.

When a loop of wire is rotated through 360º in a magnetic field, the induced voltage will be zero at which of the following points?
- A.
  
  45º
- B.
  
  90º
- C.
  
  180º
- D.
  
  270º
15.

When a loop of wire is rotated 360º in a magnetic field, at what points will the induced voltage reach its maximum (a) positive, and (b) negative values?
- A.
  
  (a) 0º , (b) 180º
- B.
  
  (a) 0º , (b) 270º
- C.
  
  (a) 90º , (b) 180º
- D.
  
  (a) 90º , (b) 270º
16.

When a coil of wire makes eight complete revolutions through a single magnetic field, (a) what total number of alternations of voltage will be generated and, (b) what total number of cycles of ac will be generated?
- A.
  
  (a) 32, (b) 16
- B.
  
  (a) 16, (b) 8
- C.
  
  (a) 8, (b) 4
- D.
  
  (a) 4, (b) 2
17.

According to the left-hand rule for generators, when your thumb points in the direction of rotation, your (a) forefinger and (b) your middle finger will indicate the relative directions of what quantities?
- A.
  
  (a) Current, (b) Magnetic flux, south to north
- B.
  
  (a) Current, (b) Magnetic flux, north to south
- C.
  
  (a) Magnetic flux, south to north, (b) Current
- D.
  
  (a) Magnetic flux, north to south, (b) Current
18.

Continuous rotation of a conductor through magnetic lines of force will produce what type of (a) voltage and (b) waveform?
- A.
  
  (a) Ac, (b) sine wave
- B.
  
  (a) Dc, (b) continuous level
- C.
  
  (a) Ac, (b) sawtooth
- D.
  
  (a) Dc, (b) pulsating wave
19.

What is the term for the number of complete cycles of ac produced in one second?
- A.
  
  Period
- B.
  
  Waveform
- C.
  
  Frequency
- D.
  
  Wavelength
20.

What is the unit of measurement for frequency?
- A.
  
  Cycle
- B.
  
  Hertz
- C.
  
  Period
- D.
  
  Maxwell
21.

A loop of wire rotating at 60 rpm in a magnetic field will produce an ac voltage of what frequency?
- A.
  
  1 Hz
- B.
  
  60 Hz
- C.
  
  120 Hz
- D.
  
  360 Hz
22.

An ac voltage of 250 hertz has a period of
- A.
  
  0.004 second
- B.
  
  0.025 second
- C.
  
  0.4 second
- D.
  
  2.5 seconds
23.

What is the approximate frequency of an ac voltage that has a period of .0006 second?
- A.
  
  6 Hz
- B.
  
  16.67 Hz
- C.
  
  600 Hz
- D.
  
  1667 Hz
24.

Component a is a measure of what quantity?
- A.
  
  Frequency
- B.
  
  Polarity
- C.
  
  Amplitude
- D.
  
  Time
25.

Component a differs from component b in which of the following characteristics.
- A.
  
  Frequency
- B.
  
  Polarity
- C.
  
  Amplitude
- D.
  
  Period