UPSC Exam > UPSC Questions > A 100-hp, 250v, 350A shunt dc motor has an ar...
Start Learning for Free
A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.
a) How many stages of starting resistance will be required to limit the current to the range specified?
b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.?
a) How many stages of starting resistance will be required to limit the current to the range specified?
b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.?
Most Upvoted Answer
A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.05...
Determining Stages of Starting Resistance
To limit the starting current to twice the rated value (i.e., 700 A for a 350 A rated motor), we first need to calculate the maximum allowable starting current.
Next, we can find the total resistance needed to limit this current using Ohm's Law (V = I × R).
Now, to determine the number of stages of resistance needed:
To limit the current effectively, a common approach is to have 3-5 stages. For example, if n = 4:
Voltage Cut-out for Each Stage
The voltage cut-out for each stage can be calculated at various armature currents until the rated current is reached.
This method ensures a smooth transition to full-load conditions, preventing excessive starting current.
To limit the starting current to twice the rated value (i.e., 700 A for a 350 A rated motor), we first need to calculate the maximum allowable starting current.
- Rated Current: 350 A
- Maximum Starting Current: 2 x 350 A = 700 A
Next, we can find the total resistance needed to limit this current using Ohm's Law (V = I × R).
- Voltage (V) = 250 V
- Armature Resistance (Ra) = 0.052 Ω
- Required Total Resistance (Rt) = V / I = 250 V / 700 A = 0.357 Ω
- Effective Resistance Needed = Rt - Ra = 0.357 Ω - 0.052 Ω = 0.305 Ω
Now, to determine the number of stages of resistance needed:
- Assuming equal segments, let the resistance of each segment be Rs.
- Let n be the number of stages.
- n × Rs = 0.305 Ω
To limit the current effectively, a common approach is to have 3-5 stages. For example, if n = 4:
- Rs = 0.305 Ω / 4 = 0.07625 Ω (approx. 0.076 Ω per segment)
Voltage Cut-out for Each Stage
The voltage cut-out for each stage can be calculated at various armature currents until the rated current is reached.
- Initial Current: 700 A
- Subsequent Current: 600 A, 500 A, etc., until 350 A.
- Voltage at cut-out stages can be calculated as: V = I × (Ra + n × Rs).
This method ensures a smooth transition to full-load conditions, preventing excessive starting current.
Attention UPSC Students!
To make sure you are not studying endlessly, EduRev has designed UPSC study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in UPSC.
|
Explore Courses for UPSC exam
|
|
Similar UPSC Doubts
Top Courses for UPSCView all
A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.?
Question Description
A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.? for UPSC 2024 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.? covers all topics & solutions for UPSC 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.?.
A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.? for UPSC 2024 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.? covers all topics & solutions for UPSC 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.?.
Solutions for A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.? in English & in Hindi are available as part of our courses for UPSC.
Download more important topics, notes, lectures and mock test series for UPSC Exam by signing up for free.
Here you can find the meaning of A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.? defined & explained in the simplest way possible. Besides giving the explanation of
A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.?, a detailed solution for A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.? has been provided alongside types of A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.? theory, EduRev gives you an
ample number of questions to practice A 100-hp, 250v, 350A shunt dc motor has an armature resistance of 0.052. It is desired to design a starter circuit for this motor which will limit the maximum starting current to twice its rated value and which will switch out sections of resistances as the armature current falls to its rated value.a) How many stages of starting resistance will be required to limit the current to the range specified?b) What must be the value of each segment of the resistor to be? At what voltage should each stage of the starting resistance be cut out.? tests, examples and also practice UPSC tests.
|
|
Explore Courses for UPSC exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup