Magnetism and Electrom Questions and Answers

Practice Mode
Showing 10 of 33 questions
Q1
Permeability is the inverse equivalent of which electrical term?
  • A Voltage
  • B Current
  • C Resistance
  • D Conductance
Answer: Option C
Q2
Which electromagnetic device uses brushes and a commutator?
  • A A speaker
  • B A dc generator
  • C A relay
  • D A solenoid
Answer: Option B
Q3
What is the flux density of a magnetic field whose flux is 3000 µWb and cross-sectional area is 0.25 m2?
  • A 12,000 mu.gifT
  • B 83,330 T
  • C 0 T
  • D More information is needed in order to find flux density.
Answer: Option A
Q4
What are the effects of moving a closed wire loop through a magnetic field?
  • A A voltage is induced in the wire.
  • B A current is induced in the wire.
  • C The polarity across the wire depends on the direction of motion.
  • D All of the above
Answer: Option D
Q5
The Hall effect
  • A is a phenomenon with no practical applications
  • B is used in various sensor applications
  • C can develop potentials of thousands of volts
  • D is the basis for solar cell operation
Answer: Option B
Q6
"Series" and "parallel" as applied to dc motors refer to
  • A the connection of the motor and controller
  • B the connection of the field coil and armature windings
  • C the connection of the brush and commutator
  • D the connection of the motor batteries
Answer: Option B
Q7
The component that produces power in an electromagnetic generator is called the
  • A armature
  • B field winding
  • C commutator
  • D brush
Answer: Option A
Q8
What is the magnetomotive force in a 150-turn coil of wire with 2 A flowing through it?
  • A 13.33 mAt
  • B 300 At
  • C 75 At
  • D 152 At
Answer: Option B
Q9
A Hall effect sensor
  • A exists only in theory
  • B is a noncontacting magnetic sensor
  • C can operate only a few times before failure
  • D produces very large voltages
Answer: Option B
Q10
Which two values are plotted on a B-H curve graph?
  • A Reluctance and flux density
  • B Permeability and reluctance
  • C Magnetizing force and permeability
  • D Flux density and magnetizing force
Answer: Option D

📚 More from Electronics

← All Topics 🎯 Practice ⏱️ Take Test 🔍 Search
Electronics
Back to Electronics
Other Subjects
Questions and Answers for Competitive Exams Various Entrance Test