Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
How will the length of the air gap in a DC electric machine affect pulsational loss in pole faces?
Answer: b Explanation: The change in air gap flux density is small when the length of the air gap is increased. This is due to slotting. The pulsational loss in the pole face decreases with an increase in air gap length.
Answer: b
See lessExplanation: The change in air gap flux density is small when the length of the air gap is increased. This is due to slotting. The pulsational loss in the pole face decreases with an increase in air gap length.
Which of these windings are said to be bifurcated windings?
Answer: a Explanation: In electric machine design whole coil windings are also called bifurcated windings. In such a winding, it can be seen that the coils that comprise a pair of pole phase group are split into 2 sets of concentric coils.
Answer: a
Explanation: In electric machine design whole coil windings are also called bifurcated windings. In such a winding, it can be seen that the coils that comprise a pair of pole phase group are split into 2 sets of concentric coils.
See lessHow should be the value of field mmf to prevent excessive distortion of field form by armature reaction in an electric machine?
Answer: a Explanation: The field mmf must be large compared to armature mmf to prevent excessive distortion of field form by armature reaction. The air gap length can be made large to reduce the distortion effect of armature reaction as a long air gap needs a large field mmf.
Answer: a
Explanation: The field mmf must be large compared to armature mmf to prevent excessive distortion of field form by armature reaction. The air gap length can be made large to reduce the distortion effect of armature reaction as a long air gap needs a large field mmf.
See lessWhich of these will increase with an increase in the number of poles?
Answer: b Explanation: The weight of field copper, armature copper, and the overall diameter of the machine decreases with an increase in the number of poles. The number of commutator segments will increase with an increase in the number of poles.
Answer: b
Explanation: The weight of field copper, armature copper, and the overall diameter of the machine decreases with an increase in the number of poles. The number of commutator segments will increase with an increase in the number of poles.
See lessWhat is the relation between hysteresis and the number of poles?
Answer: a Explanation: Keeping the core area the same, the hysteresis loss for a 4 pole machine will be half of that in a 2 pole machine. Thus, hysteresis loss decreases with an increase in the number of poles.
Answer: a
Explanation: Keeping the core area the same, the hysteresis loss for a 4 pole machine will be half of that in a 2 pole machine. Thus, hysteresis loss decreases with an increase in the number of poles.
See lessWhat are the different types of interpoles in DC electric machines?
Answer: a Explanation: Interpoles are placed in a machine to improve the commutation conditions. The two types of interpoles are Parallel sided and Tapered where tapered are generally used for large machines.
Answer: a
See lessExplanation: Interpoles are placed in a machine to improve the commutation conditions. The two types of interpoles are Parallel sided and Tapered where tapered are generally used for large machines.
What kind of layer winding in an electric machine occupies the whole slot by one coil side of the coil?
Answer: a Explanation: A single layer winding occupies the whole slot by one coil side of the coil. Such a winding is used to make open windings but is not used for closed windings.
Answer: a
Explanation: A single layer winding occupies the whole slot by one coil side of the coil. Such a winding is used to make open windings but is not used for closed windings.
See lessHow will high specific loading according to rotating electric machine affect the efficiency?
Answer: b Explanation: Higher the specific loading, lower will be the size and cost of the machine but the efficiency, power factor, commutation conditions in dc machines are affected. Thus, a suitable value of specific loadings needs to be selected.
Answer: b
See lessExplanation: Higher the specific loading, lower will be the size and cost of the machine but the efficiency, power factor, commutation conditions in dc machines are affected. Thus, a suitable value of specific loadings needs to be selected.
How will be the size and cost of a rotating electric machine that has a higher output coefficient be?
Answer: b Explanation: The rotating electric machine designed with a higher output coefficient will have a smaller size and lesser cost compared to other machines having a lower output coefficient. This is because the volume of active parts of the machine varies inversely with the output coefficientRead more
Answer: b
See lessExplanation: The rotating electric machine designed with a higher output coefficient will have a smaller size and lesser cost compared to other machines having a lower output coefficient. This is because the volume of active parts of the machine varies inversely with the output coefficient.
Which of the following is the same as the transformer emf?
Answer: a Explanation: Pulsational emf is also called the transformer emf. It is produced when the coil is stationary and flux varies with time. Such emf is produced in a transformer and no motion takes place in this machine.
Answer: a
See lessExplanation: Pulsational emf is also called the transformer emf. It is produced when the coil is stationary and flux varies with time. Such emf is produced in a transformer and no motion takes place in this machine.