Which of the following circuit is designed to dissipate heat produced in the machine?
  • a) Electric circuit
  • b) Magnetic circuit
  • c) Dielectric circuit
  • d) Thermal circuit
Which of the following materials is generally used in the design of electromagnetic machines?
  • a) Paramagnetic materials
  • b) Diamagnetic materials
  • c) Ferromagnetic materials
  • d) Core-magnetic materials
What must be mainly ensured to keep the temperature rise within limits?
  • a) Good efficiency of the machine
  • b) Proper cooling and ventilation
  • c) Proper saturation level
  • d) Good insulation
Which of the following kind of conductors will require thicker insulation?
  • a) Large sized conductor
  • b) Small-sized conductor
  • c) Conductors with high permeance
  • d) Conductors with low permeance
Which of the following factor mainly determines the type of insulation for an electrical machine?
  • a) Maximum allowable flux density
  • b) Maximum operating temperature
  • c) Maximum efficiency of the machine
  • d) Maximum allowable loss in machine
How should be the magnetic and electrical loadings in a highly efficient electric machine?
  • a) It must be small
  • b) It must be large
  • c) It must be equal to the current density
  • d) It must be equal to the flux density
What kind of emf is produced in an electric machine when the coil is stationary and flux varies with time?
  • a) Transformer emf
  • b) Motional emf
  • c) Interactional emf
  • d) Induction emf
What kind of materials are used to design electrical heating devices?
  • a) High Conductivity Materials
  • b) High Resistivity Materials
  • c) High Weldability Materials
  • d) High Solderability Materials
What are the main dimensions of a rotating electric machine?
  • a) Field diameter and Armature core length
  • b) Armature diameter and Field core length
  • c) Armature diameter and Armature core length
  • d) Field diameter and Field core length
What determines the output of a dc electric machine?
  • a) Only Total Magnetic loading
  • b) Only Total Electric loading
  • c) Total loadings
  • d) Either Total Magnetic loading or Total Electric loading
How will the size and cost of a rotating electric machine be if it is designed with greater speed?
  • c) large size and more cost
  • d) large size and less cost
  • a) small size and more cost
  • b) small size and less cost
What is the relation between the output coefficient to the volume of active parts in a rotating electric machine?
  • a) directly proportional
  • b) inversely proportional
  • c) equal to
  • d) No relation can be established
How should be the output coefficient of a rotating electric machine from an economics point of view?
  • a) High
  • c) Moderate
  • d) Output coefficient does not affect the economics
How should be the specific loadings to design a machine with reduced dimensions?
  • a) Increased values of specific loadings
  • b) Decreased values of specific loadings
  • c) Zero specific loadings
  • d) Moderate values of specific loadings
Where does maximum flux density occur in a well-designed electric machine?
  • a) In the rotor
  • b) In the air gap
  • c) In the teeth
  • d) In the poles
Which of these factors does not determine the specific magnetic loading in rotating machines?
  • a) Magnetizing current
  • b) Core loss
  • c) Maximum flux density in iron parts
  • d) Number of parallel paths
What is the other name for a short-pitched coil electrical machine?
  • a) Coiled
  • b) Commutated
  • c) Winded
  • d) Chorded
What kind of layer winding does a closed winding of an electric machine usually have?
  • a) Single layer
  • b) Double layer
  • c) Single layer or Double layer
  • d) Mixture of single layer and double layer
Why are tapered interpoles used in large DC electric machines?
  • a) To eliminate saturation at root of pole
  • b) To obtain higher speeds
  • c) To obtain maximum torque
  • d) To eliminate eddy current loss
Which part of an electric machine is designed to give the main magnetic flux?
  • a) Interpoles
  • b) Frame
  • c) Main poles
  • d) Commutator
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