Measurement Of Self Inductance By Owen Bridge

  Procedure:

  1. Apply Supply voltage (3V) from the signal generator with arbitrary frequency.

  2. Select the type of the unknown Inductor (Air Core or Iron Core) from 'Set Inductor value' tab by clicking on 'Set' button.

  3. Then switch on the supply to get millivoltmeter deflection.

  4. For Air Core experiment: Choose the values of R2 and C2, R3 and C4 from the control box below or directly put the values in the boxes of respective elements.

  5. Observe the millivoltmeter pointer to achieve "Null" or closest to "Null".

  6. If "Null" is achieved, switch to 'Measure Inductor value' tab and click on 'Simulate'. Observe calculated values of unknown Inductor (L1) and unknown Internal Resistance (R1) of the Coil. Also observe the Quality factor (or Q-factor) of the coil, which is defined as `(omegaL)/r`. where, `w=2*pi*f`.

  7. For Iron Core experiment: Follow the same procedure from step 2 to step 6.

    8. N.B.:-  Range of C4=100`pF` to 11.111`uF` (in steps of 100 `pF`).
    Range of R2, R3 and R4= `1  Ω` to `11111110  Ω`  (in steps of 1 `Ω`)

Tutorials Point

Coil Select

Voltage:

Frequency:

V

Hz

`Ω`

`Ω`

`F`

`F`

`mV`

  • Set the actual values of L1:
           Select the type of the unknown Inductor from the
           'Coil Select' box and click on the 'Set' button.
    Range of L1:      For Air Core: 45`mH`
                               For Iron Core: 450`mH`

    L1=

    `mH`

  • The current voltmeter reading is:   mv.
    Now simulate to get:
         Inductor value (in `mH`):
         Resistance value (in `Ω`):
         Quality Factor:
CONTROLS
   C2 : 100 `pF`     11.111`uF`
   R3 : 1 `Ω`     11.11111 MΩ
   R2 : 1 `Ω`     11.11111 MΩ
   C4 : 100 `pF`     11.111`uF`