# Electrical Inductors MCQ Electrical Engineering

50 Questions 30 Mins

### About Electrical Inductors

Following are some of the multiple choice questions on the Electrical Inductors with answers that will help the students in developing their knowledge.

## Electrical Inductors MCQ

• I
• Z
• XL
• L

### 2. If the capacitance of a capacitor is 47μF, and the voltage difference across the capacitor terminals is 6V, then the energy stored in that capacitor is:

• 846×10-6Joule
• 7.23×10-3 Joule
• 6.76×10-5Joule
• 5.94×10-2Joule

• C = Q/V
• V = C×Q
• Q = C/V
• Q = V/C

### 4. Lamination of transformer core is made of

• Cast Iron
• Silicon Steel
• Aluminium
• Cast Steel

• Open
• Short
• Polar
• Non-polar

### 6. If supply frequency of a transformer increases, the secondary output voltage of the transformer

• Increase
• Decrease
• Remain the same
• Any of the above

### 7. Inductor stores energy in the form of

• Electric field
• Electromagnetic field
• Magnetic field
• None of the above

### 8. If in an iron cored coil the iron core is removed so as to make the air cored coil, the inductance of the coil will be

• More
• Less
• The same
• None of these

### 9. ------------------------ is created out of two metal plates and an insulating material called a dielectric.

• An inductor
• A capacitor
• A fixed resistor
• A variable resistor

### 10. The production of a voltage across an inductor as a result of its own expanding or contracting magnetic field is called ____.

• Flux density
• Self-inductance
• Counter emf
• Faraday's second law

### 11. To demonstrate static electricity, a teacher takes an inflated balloon and rubs it against his hair. The rubber balloon picks up electrons from his hair, which makes his hair have

• a net negative charge
• a magnetic force
• a net positive charge
• None of these

### 12. Neutrons have a __________ charge.

• Negative
• Positive
• Neutral
• None of these

### 13. Why do socks stick together when they come out of the dryer?

• One has a negative charge and the other has a positive charge
• Both have negative charges
• Both have positive charges
• All of above

• closer
• further
• stronger
• weaker

### 15. Charged objects can be attracted to:

• Neutral objects
• Objects with the opposite charge
• Both
• Both A & B

### 16. The transfer of what type of atomic particle is responsible for the static charges on objects?

• neutrons
• protons
• electrons
• none of these

### 17. What types of charges repel?

• Positive and Positive
• Positive and Neutral
• Negative and Neutral
• Neutral and Neutral

### 18. If a substance has a higher number of electrons than protons on its surface, what type of charge does it have?

• A positive charge.
• A negative charge.
• A neutral charge
• No charge at all

### 19. Mutual inductance between two magnetically coupled coils depends on

• Permeability of the core material
• Number of turns of the coils
• Cross sectional area of their common core
• All of the above

### 20. Which of the following does not change in an ordinary transformer........

• .Frequency
• .Voltage
• .Current
• Any of the above

• henry
• dielectric
• core
• center

### 22. Inductance value is also affected by permeability, , cross sectional area and____________.

• impedance
• the alternating current
• the number of turns
• impedance

### 23. Two common inductor cores are ___________.

• air and iron
• carbon and copper
• plastic and Teflon
• desiccant and lead

### 24. Capacitors are identified by which two values?

• Farads and watts
• Maxwells and current
• Farads and voltage
• Watts and henries

• air
• ceramic
• glass
• copper

• Maxwells
• Henries
• Watts

### 27. The ability of a capacitor to store a charge is called __________.

• Resistance
• Capacitance
• Inductance
• Dielectric constant

• 500 J
• 10000 J
• 12500 J
• 25000 J

### 29. An inductor with an inductance of 5mH is connected in series with a 20 ohm resistor.What is the time constant of the inductor?

• 2.5 x 10^-4 s
• 4 x 10^4 s
• 0.1s
• 100s

• 0.333 V
• 3 V
• 300 V
• 0.3 V

• Ohm
• Henry
• Ampere turns
• Webers/meter

### 32. The electrical energy consumed by a coil is stored in the form of:

• an electrical field
• a force field
• an electrostatic field
• a magnetic field

### 33. The voltage induced across an inductor as its magnetic field collapses is called ____.

• Counter emf
• Transition voltage
• Reverse voltage
• Counter voltage

### 34. Transformer core are laminated in order to

• reduce hysteresis loss
• reduce hysteresis & eddy current loss
• minimize eddy current loss
• Copper loss

### 35. Inductor cores can be made of

• air
• iron
• magnetic materials
• all of these

• 1/2πfL
• 2πfL
• f/2πL
• X

### 37. Inductors connected in series will

• be the reciprocal of the sum total of inductors for final value of Henrys
• be the sum total of inductors for final value of Henrys
• be the reciprocal of the sum of reciprocals of each inductor
• act as a voltage divider network

### 38. The rate of change of ? determines the generated EMF in an inductor

• voltage and current
• current and time
• voltage and time
• back EMF and current

### 39. An inductor stores energy

• in the skin of the conductor
• in the magnetospheric region of the electrons
• in the dielectric material
• in a magnetic field

### 40. Your grade for inductors will depend highly on

• how much I like you
• how much you study
• how lucky you are
• luck of the draw

### 41. ELI went to visit ICE and the two really resonated together! As a result, a ???? circuit was born.

• Cole-Porter phase invertor
• rejector
• tank
• Dailey-Vincent oscillator

### 42. Skin effect is a concern

• at lower frequencies
• cable is exposed to UV rays
• at higher frequencies
• there are many eddy currents present

### 43. Skin effects tends to

• heat the conductor
• cause a huge loss of efficiency
• concentrate electrons on the outer edge (skin) of the conductor
• cause signal distortion

### 44. The "Q" of an inductor is expressed in units of

• Henries
• Faroids
• Reluctance
• Q has no units

### 45. An inductor tends to

• reject low frequencies
• reject high frequencies
• pass a band of frequencies
• reject a band of frequencies

### 46. Magnetic coupling is when

• magnetic lines link
• two magnets get married
• two magnets are placed end-to-end
• magnets line-up and repel each other

• T = 1/RL
• T = RL
• t = R/L
• t = L/R

### 48. The magnetic field can be increased by adding

• removing the core
• adding a core
• decreasing the number of windings
• changing the diameter of the wire insulation

• Henry
• George
• Jones

• BEMF
• EMF
• MFF
• BPM