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1. A 4 pole, 220 V, 10 H.P, d.c. shunt motor is rotating at a speed of 320 rpm. Then the developed useful torque is

2. A 4 pole, lap wound d.c. motor drawing an armature current of 20 A has 360 conductors. If the flux per pole is

0.015 Wb then the gross torque developed by the armature of motor is

3. A 220 V, d.c. motor draws an armature current of 20 A. Its armature resistance is 0.6 ohm. Then the induced emf

in the motor will be

4. A 4 pole, lap wound d.c. generators has 40 coils with 8 turns per coils. It is driven at 1200 rpm. If the flux per pole

is 0.022 Wb, then the generated emf is

5. A 4 pole, d.c. generator has a wave wound armature with 812 conductors. The flux per pole is 0.014 Wb. The

speed at which it should be run to generate 240 V on no load is

6. A 240 V, 17 kW d.c. shunt motor draws an armature current of 80 A at full load. The armature and shunt field

resistances are 0.2 ohm and 195 ohm respectively. The efficiency of motor at full load is

7. 240 V, 17 kW d.c. shunt motor draws an armature current of 80 A at full load. The armature and shunt field

resistances are 0.2 ohm and 195 ohm respectively. The rotational mechanical losses at full load is

8. A 120 V d.c. shunt motor runs at speed of 1200 rpm. When the motor is operated unloaded but an additional resistance of 4 ohm is connected in series with the shunt field, then the speed increases and reaches to 1370 rpm with the same terminal voltage. The value of shunt field resistance is

9. A d.c. shunt generator delivers 190 A at a terminal voltage of 220 V. The copper losses and stray losses are 2000 W

and 1000 W respectively. The efficiency of the generator is

Answer 1