Electrical Machines In a DC machine current and emf in armature are alternating. emf in armature conductors and at the terminals is alternating. current and emf in armature are unidirectional current and emf at the terminals are alternating. current and emf in armature are alternating. emf in armature conductors and at the terminals is alternating. current and emf in armature are unidirectional current and emf at the terminals are alternating. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V dc series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 Ω. The value of resistance which must be added to obtain rated torque at 1000 rpm is 2.2 Ω 1.9 Ω 6 Ω 5.7 Ω 2.2 Ω 1.9 Ω 6 Ω 5.7 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Wave winding is employed in DC machine of low current and high voltage rating. low current and low voltage rating. high current and low voltage rating. high current and low voltage rating. low current and high voltage rating. low current and low voltage rating. high current and low voltage rating. high current and low voltage rating. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the source voltage of a DC motor is increased, which of the following will decrease? Starting torque, operating speed, full load current. Full load current. Starting torque. Operating speed. Starting torque, operating speed, full load current. Full load current. Starting torque. Operating speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements, 1, 2 and 4 are correct 2, 3 and 4 are correct 1, 2 and 3 are correct 1 and 4 are correct 1, 2 and 4 are correct 2, 3 and 4 are correct 1, 2 and 3 are correct 1 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum power developed by a synchronous motor depends on supply voltage and excitation supply voltage and load angle excitation and load angle supply voltage, load angle and excitation supply voltage and excitation supply voltage and load angle excitation and load angle supply voltage, load angle and excitation ANSWER DOWNLOAD EXAMIANS APP
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