Thank you.
- Please Answer Each Part Of The Question In A Detailed Manner Thank You 1 (200.64 KiB) Viewed 19 times
Please answer each part of the question in a detailed manner. Thank you.
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Please answer each part of the question in a detailed manner. Thank you.
Please answer each part of the question in a detailed manner.
Thank you.
4. (a) The armature terminals of a dc shunt motor are connected to a dc supply of 220 V. The armature winding resistance and field winding resistance are 0.2 2 and 220 22, respectively. The rotational losses of the motor are 500 W. If the armature current is 100 A when the motor is running at a speed of 1200 rpm, determine (i) the load torque, and (ii) the input power of the motor. (8 Marks) (b) A dc shunt motor has an armature winding resistance of 0.8 2. The armature terminals are connected to a dc supply of 500 V and the motor is running at a speed of 1500 rpm when the armature current is 85 A. (i) Determine the torque developed. (ii) If the field flux is reduced by 10 % due to the addition of a resistance in series with the field windings, determine the armature current and the speed of the motor. Assume that the torque developed is the same as in part (i). (8 Marks) (c) The armature winding resistance of a separately-excited de generator is 0.4 12. The field circuit is connected to a 120 V dc supply. Rotational losses of the machine are 100 W. The generator is driven at a speed of 1200 rpm by an external prime mover and the no-load terminal voltage is 120 V for a field current of 0.5 A. A load resistance of 412 is connected across the armature terminals. The effects of armature reaction can be neglected. (i) Determine the output power of the generator with the external prime mover running at a speed of 1200 rpm and the field current is 0.5 A. (ii) The speed of the external prime mover is now decreased to 1000 rpm with the field current remaining at 0.5 A. Determine the efficiency of the generator. (9 Marks)
Thank you.
4. (a) The armature terminals of a dc shunt motor are connected to a dc supply of 220 V. The armature winding resistance and field winding resistance are 0.2 2 and 220 22, respectively. The rotational losses of the motor are 500 W. If the armature current is 100 A when the motor is running at a speed of 1200 rpm, determine (i) the load torque, and (ii) the input power of the motor. (8 Marks) (b) A dc shunt motor has an armature winding resistance of 0.8 2. The armature terminals are connected to a dc supply of 500 V and the motor is running at a speed of 1500 rpm when the armature current is 85 A. (i) Determine the torque developed. (ii) If the field flux is reduced by 10 % due to the addition of a resistance in series with the field windings, determine the armature current and the speed of the motor. Assume that the torque developed is the same as in part (i). (8 Marks) (c) The armature winding resistance of a separately-excited de generator is 0.4 12. The field circuit is connected to a 120 V dc supply. Rotational losses of the machine are 100 W. The generator is driven at a speed of 1200 rpm by an external prime mover and the no-load terminal voltage is 120 V for a field current of 0.5 A. A load resistance of 412 is connected across the armature terminals. The effects of armature reaction can be neglected. (i) Determine the output power of the generator with the external prime mover running at a speed of 1200 rpm and the field current is 0.5 A. (ii) The speed of the external prime mover is now decreased to 1000 rpm with the field current remaining at 0.5 A. Determine the efficiency of the generator. (9 Marks)
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