Some Instruments for Physics

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Some Instruments for Physics
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(A) Vernier Calipers ( ???? )
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(A) Vernier Calipers ( ???? )

• measuring length, external diameter or internal
  diameter of objects with reading down to 0.1 mm.

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(B) Micrometer gauge ( ??? )
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(B) Micrometer gauge ( ??? )

• measuring length or external diameter of objects
  with reading down to 0.01 mm.

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(B) Micrometer gauge ( ??? )

• Clamp the object to be measured. Hold it tight by
  moving the handle until Click is heard.
• Hence length P Q 2.5 0.33 2.83 mm

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Cathode Ray Oscilloscope (CRO)
Basically, CRO is a voltmeter with a
screen. CRO voltmeter screen Therefore, a
CRO can display the voltage against time.
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• GND, A.C. mode and D.C. mode
• Input voltage

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The operation ( ?? ) of C.R.O.

• Usual adjustments
• Either A.C. or D.C. mode is chosen.
• Trig level ( ???? ) to AUTO position.
• All verniers ( ?? ) to CAL position.
• Set Zero by shorting ( ?? ) the Y?input and
  Ground, followed by adjusting the Y?shift.

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(a) Measuring d.c. voltage as voltmeter ( ??? )

• Input voltage is connected across to Y-input for
  positive terminal ( ??? ) and to ground (NOT
  X-input) for negative terminal.
• Set a suitable voltage gain/sensitivity ( ???? ).
• Every time the voltage gain is changed, the CRO
  has to be Set Zero again.
• (Time base ?? can either be on or off.)

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(b) Measuring a.c. peak voltage ( ???? )

• Input voltage is connected across to Y-input and
  ground.
• Set a suitable voltage gain.
• Every time the voltage gain is changed, the CRO
  has to be Set Zero again.
• (Time base may be off. i.e. a vertical line is
  seen.)

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Measuring a.c. frequency or displaying waveform

• Time base is on and set a suitable time base.

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Multimeter ( ???? )

• A meter which has been adapt for measuring
  current, voltmeter and resistance.

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(No Transcript)
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Multimeter used as a D.C. voltmeter

• Set zero and turn S to the greatest voltage range
  of DC V.
• Connect the ? and ? terminals of the meter as
  right for the p.d. concerned
• Turn S to get the greatest possible deflection
  (greatest sensitivity)
• Read the selected f.s.d. voltage

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Multimeter used as a D.C. ammeter

• Set zero and turn S to the greatest voltage range
  of DC A.
• Connect the ? and ? terminals of the meter as
  right for the p.d. concerned
• Turn S to get the greatest possible deflection
  (greatest sensitivity)
• Read the selected f.s.d. voltage

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Multimeter used as an Ohmmeter

• Turn S to the ohm range
• Short the ? and ? terminals of the meter and
  adjust 0 ? ADJ to set the pointer to 0 ?.
• Connect the unknown resistor R

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• Turn S to get the greatest possible deflection
• Every time the ohm range is changed, it has to
  set 0 ? ADJ again.
• Read the ohm range
• Observe the reading from the ohm scale.