Electrical Problems

A 3 ∅ induction motor with 4 poles is supplied from the alternator having 6 poles running at 1000 rpm. Calculate synchronous speed of the induction motor its speed when slip is 0.04 and frequency of the rotor EMF when the speed is 600 rpm Problem Question A 3 ∅ induction motor with 4 poles is supplied from the alternator having 6 poles running at 1000 rpm. Calculate synchronous speed of the induction motor its speed when slip is 0.04…

The frequency of the EMF in the stator of a 4 pole induction motor is 50 Hz and in the rotor is 1.5 Hz. What is the slip and what speed is the motor running? Problem Question The frequency of the EMF in the stator of a 4 pole induction motor is 50 Hz and in the rotor is 1.5 Hz. What is the slip and what speed is the motor running? Topic Induction Motor Induction Motor Problems The frequency…

If a 6 pole Induction motor is supplied from a 3∅, 50 Hz supply has a rotor frequency of 2.3 Hz, Calculate (i) Percentage slip (ii) Speed of the motor Problem Question If a 6 pole Induction motor is supplied from a 3∅, 50 Hz supply has a rotor frequency of 2.3 Hz, Calculate (i) Percentage slip (ii) Speed of the motor Topic Induction Motor Induction Motor Problems The frequency of the EMF in the stator of a 4 pole…

Find the efficiency of 150 KVA, 1∅ transformer at (i) Full load UPF (ii) 50% of full load at 0.8 p.f, if the copper loss at full load is 1600 W and iron loss is 1400W Problem Question Find the efficiency of 150 KVA, 1∅ transformer at (i) Full load UPF (ii) 50% of full load at 0.8 p.f, if the copper loss at full load is 1600 W and iron loss is 1400W Topic Transformer Transformer Problems The maximum…

A 20KVA, 1∅ transformer has 200 turns on primary and 40 turns on secondary. The primary is connected to 1000V, 50Hz supply. Find the secondary voltage, rated current flowing through two windings and the maximum value of flux Problem Question A 20KVA, 1∅ transformer has 200 turns on primary and 40 turns on secondary. The primary is connected to 1000V, 50Hz supply. Find the secondary voltage, rated current flowing through two windings and the maximum value of flux Topic Transformer…

A 10KVA, 1∅ transformer has a primary winding of 300 turns and secondary winding of 750 turns, cross sectional area of 64 cm^2. If primary voltage is 440 V at 50 Hz, find maximum flux density in the core, EMF induced in the secondary of transformer. At 0.8 lag p.f, Calculate the efficiency of transformer if full load copper loss is 400W and iron-loss is 200W Problem Question A 10KVA, 1∅ transformer has a primary winding of 300 turns and…

A 40 KVA, 1∅ Transformer has core loss of 450W and full load copper loss 850W. If the power factor of the load is 0.8, Calculate (i) Full load efficiency (ii) Maximum efficiency at UPF (iii) Load for maximum efficiency Problem Question A 40 KVA, 1∅ Transformer has core loss of 450W and full load copper loss 850W. If the power factor of the load is 0.8, Calculate (i) Full load efficiency (ii) Maximum efficiency at UPF (iii) Load for…

A 1∅, 20 KVA transformer has 1000 primary turns and 2500 secondary turns the net cross sectional area of the core is 100 cm^2. When the primary winding is connected to 550 V, 50Hz supply, Calculate (i) The maximum value of flux density in the core (ii) The voltage induced in the secondary winding (iii) The primary and secondary full load currents Problem Question A 1∅, 20 KVA transformer has 1000 primary turns and 2500 secondary turns the net cross…

A 500KVA transformer has an efficiency of 92% at full load unity power factor and at half full load 0.9 p.f. Determine it’s efficiency at 80% full load and 0.95 p.f Problem Question A 500KVA transformer has an efficiency of 92% at full load unity power factor and at half full load 0.9 p.f. Determine it’s efficiency at 80% full load and 0.95 p.f Topic Transformer Transformer Problems The maximum efficiency at full load and unity power factor of a…

The maximum efficiency at full load and unity power factor of a 1∅, 25 KVA, 50/1000V, 50Hz transformer is 98%. Determine the efficiency at (i) 75% load 0.9 p.f (ii) 50% load 0.9 p.f (iii) 25% load 0.6 p.f Problem Question The maximum efficiency at full load and unity power factor of a 1∅, 25 KVA, 50/1000V, 50Hz transformer is 98%. Determine the efficiency at (i) 75% load 0.9 p.f (ii) 50% load 0.9 p.f (iii) 25% load 0.6 p.f…

A 3∅, 4 pole, 50 Hz star connected alternator has an armature with 2 slots per pole per phase and 40 conductors per slot. Calculate the EMF generated if the flux per pole is 0.06 wb distributed sinusoidally Problem Question A 3∅, 4 pole, 50 Hz star connected alternator has an armature with 2 slots per pole per phase and 40 conductors per slot. Calculate the EMF generated if the flux per pole is 0.06 wb distributed sinusoidally Topic Alternators…

A 6 pole, 3∅, 50 Hz alternator has 12 slots per pole & 4 conductors per slot. The winding is 5/6 full pitched, a flux of 25 mwb is sinusoidally distributed along the air gap. Determine the line EMF, if the alternator is star connected Problem Question A 6 pole, 3∅, 50 Hz alternator has 12 slots per pole & 4 conductors per slot. The winding is 5/6 full pitched, a flux of 25 mwb is sinusoidally distributed along the…

A 2 pole, 3∅ running at 3000 rpm has 42 slots with 2 conductors per slot. Calculate the flux per pole required to generate a line voltage of 2300 V. Assume Kd=0.952, Kp=0.956. The armature is star connected Problem Question A 2 pole, 3∅ running at 3000 rpm has 42 slots with 2 conductors per slot. Calculate the flux per pole required to generate a line voltage of 2300 V. Assume Kd=0.952, Kp=0.956. The armature is star connected Topic Alternators…

A 3Φ, 4 pole, 50Hz star connected alternator has 36 slots with 30 conductors per slots. The useful flux per pole  is 0.05 wb. Find synchronous speed and line voltage on no-load. Assume Kw=0.96 Problem Question A 3Φ, 4 pole, 50Hz star connected alternator has 36 slots with 30 conductors per slots. The useful flux per pole  is 0.05 wb. Find synchronous speed and line voltage on no-load. Assume Kw=0.96 Topic Alternators Alternators Problems A 12 pole 500 rpm, star…

The stator of a 3∅, 8 pole, 750 rpm alternator has 72 slots, each of which contains 10 conductors. Calculate the RMS values of EMF per phase is flux per pole is 0.1 wb sinusoidally distributed. Assume full pitch coils and Kd as 0.96 Problem Question The stator of a 3∅, 8 pole, 750 rpm alternator has 72 slots, each of which contains 10 conductors. Calculate the RMS values of EMF per phase is flux per pole is 0.1 wb…

A 6 pole Υ connected, 3phase, 50Hz alternator has 12 slots per pole and 4 conductors per slot.  A flux of 25mwb is sinusoidally distributed along the air gap. Determine the (i) Phase EMF (ii) Line EMF.  Assume coils are full pitched and winding factor as 0.96 Problem Question A 6 pole Υ connected, 3phase, 50Hz alternator has 12 slots per pole and 4 conductors per slot.  A flux of 25mwb is sinusoidally distributed along the air gap. Determine the…

A 3∅, 6 pole star connected alternator has an armature with 90 slots and 12 conductors per slot, it revolves at 1000 rpm, the flux per pole being 0.05 wb. Calculate the line value of the EMF generated, if = 0.96  and  = 0.97 Problem Question A 3∅, 6 pole star connected alternator has an armature with 90 slots and 12 conductors per slot, it revolves at 1000 rpm, the flux per pole being 0.05 wb. Calculate the line value…

A 12 pole 500 rpm, star connected alternator has slots with 15 conductors per slot. The flux per pole is 0.02 wb .The winding factor is 0.97 and pitch factor is 0.98. Calculate the phase EMF and line EMF Problem Question A 12 pole 500 rpm, star connected alternator has slots with 15 conductors per slot. The flux per pole is 0.02 wb .The winding factor is 0.97 and pitch factor is 0.98. Calculate the phase EMF and line EMF…