22/05/2023
: Magnetic Circuits: Flux Linkage, inductance, and Energy
1. Which of the following factors affects the inductance of an air-core coil the most?
a) The number of turns in the coil
b) The cross-sectional area of the coil
c) The length of the coil
d) The permeability of the surrounding medium
2. The magnetic field strength within a magnetic material is primarily determined by:
a) The current flowing through the material
b) The magnetic flux density of the material
c) The permeability of the material
d) The resistance of the material
3. When an inductor is subjected to a sinusoidal current, the magnetic flux density within the inductor:
a) Lags behind the current by 90 degrees
b) Leads the current by 90 degrees
c) Is in phase with the current
d) Is independent of the current frequency
4. Which materials would be most suitable for a high-frequency inductor core?
a) Soft iron
b) Ferrite
c) Copper
d) Aluminum
5. The energy stored in an inductor can be increased by:
a) Increasing the number of turns in the coil
b) Decreasing the core material's magnetic permeability
c) Decreasing the current flowing through the inductor
d) Increasing the resistance of the inductor
6. The concept of mutual inductance is most closely associated with:
a) Transformers
b) Inductor losses
c) Eddy currents
d) Magnetic hysteresis
7. In a magnetic circuit, the reluctance is analogous to:
a) Resistance in an electric circuit
b) Capacitance in an electric circuit
c) Conductance in an electric circuit
d) Impedance in an electric circuit
8. Which of the following factors would decrease the self-inductance of a solenoid?
a) Increasing the number of turns
b) Decreasing the length of the solenoid
c) Using a core material with higher permeability
d) Increasing the current flowing through the solenoid
9. The rate at which magnetic energy is transferred into or out of an inductor is determined by:
a) Power factor
b) Reactive power
c) Instantaneous power
d) Complex power
10. The concept of magnetic saturation refers to:
a) The point at which an inductor becomes open-circuited
b) The point at which the magnetic field within a material cannot increase further with an increase in current
c) The phenomenon of magnetic field leakage in a magnetic circuit
d) The hysteresis loss in a magnetic material
:
1. a) The number of turns in the coil
2. c) The permeability of the material
3. a) Lags behind the current by 90 degrees
4. b) Ferrite
5. a) Increasing the number of turns in the coil
6. a) Transformers
7. a) Resistance in an electric circuit
8. b) Decreasing the length of the solenoid
9. c) Instantaneous power
10. b) The point at which the magnetic field within a material cannot increase further with an increase in current
