12.4 Inductance

• Inductance is measured in henries
• The magnetic field strength in the magnetic flux formula is measured in teslas
• What is the formula for calculating inductance?

  L = NΦ / I
• What is magnetic flux linkage used in the inductance formula?

  To calculate inductance
• A material with high permeability enhances the magnetic field within a coil.


  True
• A larger coil area and shorter coil length reduce inductance.

  False
• Inductance is calculated using the formula L = NΦ / I.

  True
• Magnetic flux is calculated using the formula Φ = BA cos θ.


  True
• Increasing the number of turns in a coil decreases its inductance.

  False
• Why does a core material with high permeability increase inductance?

  Enhances the magnetic field
• Inductance is measured in henries
• Match the property with its description or unit:

  Self-inductance ↔️ Opposition to changes in its own current

  Induced EMF ↔️ Voltage created by changing current

  Factors ↔️ Number of turns, coil geometry, core material
• Mutual inductance is based on Faraday's Law of Induction.


  True
• A smaller distance between two coils increases mutual inductance.


  True
• What is the formula for inductance (L) in terms of magnetic flux (Φ), number of turns (N), and current (I)?

  $L =$$\frac{N \Phi}{I}$
• A coil with an inductance of 2 H experiences a current change from 2 A to 5 A in 0.1 seconds. The induced EMF is -60 V
• What is magnetic flux a measure of?

  Magnetic field through an area
• How is magnetic flux linkage related to inductance?

  Directly proportional
• In the inductance formula, 'N' represents the number of turns
• Match the factor affecting inductance with its effect:

  Number of turns ↔️ Increases inductance

  Coil geometry ↔️ Larger area, shorter length increases inductance

  Core material ↔️ Higher permeability increases inductance
• What effect does a high permeability material have on the magnetic field within a coil?

  Enhances the magnetic field
• What property of a core material enhances inductance in a coil?

  High permeability
• In what units is inductance measured?

  Henries (H)
• What is the formula for inductance in terms of magnetic flux linkage and current?

  L = NΦ / I
• What are the three main factors affecting inductance?

  Number of turns, coil geometry, core material
• Match the factor affecting inductance with its description:

  Number of turns ↔️ More turns in the coil

  Coil geometry ↔️ Larger area and shorter length

  Core material ↔️ Higher permeability material
• What is the formula relating induced EMF to the rate of change of current in self-inductance?

  $ε =$$- L \cdot \frac{dI}{dt}$
• What is mutual inductance?

  Voltage induced in a nearby coil
• The induced EMF in the second coil due to mutual inductance is given by $\varepsilon_{2} =$$- M \cdot \frac{dI_{1}}{dt}$, where M is the mutual inductance
• Higher permeability of the surrounding material increases mutual inductance
• Inductance is measured in henries.


  True
• A coil with 300 turns, magnetic flux of 0.05 Wb, and current of 1.5 A has an inductance of 10 H.

  True
• What is inductance a measure of?

  Coil's opposition to current changes
• Magnetic flux is measured in webers (Wb).

  True
• The magnetic flux through an area is maximum when the angle between the field and the area is 0 degrees.


  True
• Arrange the factors affecting magnetic flux in order of their effect:

  1️⃣ Magnetic field strength

  2️⃣ Area

  3️⃣ Angle between field and area
• A larger coil area and shorter coil length increase the inductance
• More turns in a coil increase the inductance because they create more magnetic flux linkage
• Inductance is the measure of a coil's opposition to changes in current
• Magnetic flux linkage is the total magnetic flux passing through all turns