Electrical Machines The volt-ampere euation for a long-shunt compound motor is given by Vt = Ea + Ia(ra + rs) Vt= Ea– Iara Vt = Ea + Iara+ ILrs Vt= Ea + Iara Vt = Ea + Ia(ra + rs) Vt= Ea– Iara Vt = Ea + Iara+ ILrs Vt= Ea + Iara ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 2 pole synchronous machine is operating at 3000 rpm. Find the relation between electrical angular momentum (ωe) and mechanical angular momentum (ωm) ? ωe = 2*ωm ωe = 1/2*ωm ωe = ωm ωe = 4*ωm ωe = 2*ωm ωe = 1/2*ωm ωe = ωm ωe = 4*ωm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The external resistance to be added in the armature circuit to limit the armature current to 125% of its rated value is 31.1 Ω 31.9 Ω 15.9 Ω 15.1 Ω 31.1 Ω 31.9 Ω 15.9 Ω 15.1 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A short-shunt cumulatively-compounded dc generator builds up a voltage of 220 V at no load at rated speed. If it is operated as a differentially compounded generator, other things remaining the same, it would build up more than 220 V somewhat less than 220 V 220 V 6 V more than 220 V somewhat less than 220 V 220 V 6 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following bearings and their uses are correct neither 1 nor 2 both A and B roller bearings → large machines ball bearings → small machines neither 1 nor 2 both A and B roller bearings → large machines ball bearings → small machines ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately excited DC motor has an armature resistance of 0.5 Ohm. The supply voltage is 250V. Armature current is 20A and the speed of rotation is 1500 rpm. Find the torque developed? 16.55 Nm Zero 15.28 Nm 15.6 Nm 16.55 Nm Zero 15.28 Nm 15.6 Nm ANSWER DOWNLOAD EXAMIANS APP
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