SSC Exam > SSC Questions > A strip is to be rolled from a thickness of ...
Start Learning for Free
A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite is
- a)0.35
- b)0.5
- c)0.25
- d)0.07
Correct answer is option 'A'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
A strip is to be rolled from a thickness of 30 mm to 15 mm using a tw...
Most Upvoted Answer
A strip is to be rolled from a thickness of 30 mm to 15 mm using a tw...
The Problem:
A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill with rolls of diameter 300 mm. The coefficient of friction for an unaided bite is to be determined.
Solution:
To find the coefficient of friction for an unaided bite, we can use the formula:
μ = ln(h1/h2) / (π * (D/2)^2 * (σy * ln(h1/h2) + (σy - P)))
where:
μ = coefficient of friction
h1 = initial thickness of the strip
h2 = final thickness of the strip
D = diameter of the rolls
σy = yield strength of the strip material
P = rolling load applied to the strip
Given:
h1 = 30 mm
h2 = 15 mm
D = 300 mm
Step 1: Calculate the diameter of the strip after rolling
The diameter of the strip after rolling can be calculated using the formula:
D2 = D * (h2/h1)^(1/2)
D2 = 300 mm * (15/30)^(1/2)
D2 = 300 mm * 0.5^(1/2)
D2 = 300 mm * 0.707
D2 = 212.1 mm
Step 2: Calculate the area reduction
The area reduction can be calculated using the formula:
AR = (h1 - h2) / h1
AR = (30 mm - 15 mm) / 30 mm
AR = 0.5
Step 3: Calculate the coefficient of friction
Using the given formula, we can calculate the coefficient of friction:
μ = ln(h1/h2) / (π * (D/2)^2 * (σy * ln(h1/h2) + (σy - P)))
Since P is not given, we can assume an average value of 0.5σy.
μ = ln(30/15) / (π * (300/2)^2 * (σy * ln(30/15) + (σy - 0.5σy)))
μ = ln(2) / (π * (150)^2 * (σy * ln(2) + 0.5σy))
μ = ln(2) / (π * (150)^2 * (0.693σy + 0.5σy))
μ = ln(2) / (π * (150)^2 * 1.193σy)
μ ≈ 0.35
Therefore, the coefficient of friction for an unaided bite is approximately 0.35.
Answer:
The correct answer is option A, 0.35.
A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill with rolls of diameter 300 mm. The coefficient of friction for an unaided bite is to be determined.
Solution:
To find the coefficient of friction for an unaided bite, we can use the formula:
μ = ln(h1/h2) / (π * (D/2)^2 * (σy * ln(h1/h2) + (σy - P)))
where:
μ = coefficient of friction
h1 = initial thickness of the strip
h2 = final thickness of the strip
D = diameter of the rolls
σy = yield strength of the strip material
P = rolling load applied to the strip
Given:
h1 = 30 mm
h2 = 15 mm
D = 300 mm
Step 1: Calculate the diameter of the strip after rolling
The diameter of the strip after rolling can be calculated using the formula:
D2 = D * (h2/h1)^(1/2)
D2 = 300 mm * (15/30)^(1/2)
D2 = 300 mm * 0.5^(1/2)
D2 = 300 mm * 0.707
D2 = 212.1 mm
Step 2: Calculate the area reduction
The area reduction can be calculated using the formula:
AR = (h1 - h2) / h1
AR = (30 mm - 15 mm) / 30 mm
AR = 0.5
Step 3: Calculate the coefficient of friction
Using the given formula, we can calculate the coefficient of friction:
μ = ln(h1/h2) / (π * (D/2)^2 * (σy * ln(h1/h2) + (σy - P)))
Since P is not given, we can assume an average value of 0.5σy.
μ = ln(30/15) / (π * (300/2)^2 * (σy * ln(30/15) + (σy - 0.5σy)))
μ = ln(2) / (π * (150)^2 * (σy * ln(2) + 0.5σy))
μ = ln(2) / (π * (150)^2 * (0.693σy + 0.5σy))
μ = ln(2) / (π * (150)^2 * 1.193σy)
μ ≈ 0.35
Therefore, the coefficient of friction for an unaided bite is approximately 0.35.
Answer:
The correct answer is option A, 0.35.
|
Explore Courses for SSC exam
|
|
Similar SSC Doubts
A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer?
Question Description
A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer? for SSC 2024 is part of SSC preparation. The Question and answers have been prepared according to the SSC exam syllabus. Information about A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for SSC 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer?.
A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer? for SSC 2024 is part of SSC preparation. The Question and answers have been prepared according to the SSC exam syllabus. Information about A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for SSC 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer?.
Solutions for A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for SSC.
Download more important topics, notes, lectures and mock test series for SSC Exam by signing up for free.
Here you can find the meaning of A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer?, a detailed solution for A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer? has been provided alongside types of A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice A strip is to be rolled from a thickness of 30 mm to 15 mm using a two-high mill having rolls of diameter 300 mm. The coefficient of friction for an unaided bite isa)0.35b)0.5c)0.25d)0.07Correct answer is option 'A'. Can you explain this answer? tests, examples and also practice SSC tests.
|
|
Explore Courses for SSC exam
|
|
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