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# Test: Block Brake

## 10 Questions MCQ Test Machine Design | Test: Block Brake

Description
This mock test of Test: Block Brake for Mechanical Engineering helps you for every Mechanical Engineering entrance exam. This contains 10 Multiple Choice Questions for Mechanical Engineering Test: Block Brake (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Block Brake quiz give you a good mix of easy questions and tough questions. Mechanical Engineering students definitely take this Test: Block Brake exercise for a better result in the exam. You can find other Test: Block Brake extra questions, long questions & short questions for Mechanical Engineering on EduRev as well by searching above.
QUESTION: 1

### Block brakes are never used in railway trains.

Solution:

Explanation: Blocks brakes are commonly employed in railway trains.

QUESTION: 2

### If torque capacity of a block brake is 240N-m and radius of drum is 210mm with coefficient of friction 0.4.

Solution:

Explanation: N=M/μR.

QUESTION: 3

### If initially drum of radius 200mm is rotating at 100rpm, then calculate the heat generated if frictional force acting is 1140N.

Solution:

Explanation: Heat=Frictional forcexaverage velocity.

QUESTION: 4

In a block brake with short shoe, it is assumed that friction force and normal reaction are concentrated at the midpoint of the shoe.

Solution:

Explanation: The angle of contact is less than 45⁰ and hence the assumption is valid.

QUESTION: 5

The pressure intensity at an element on long shoe brake varies directly with the sin of the pressure angle of the element of friction lining.

Solution:

Explanation: p=Cxcos(Ǿ).

QUESTION: 6

The equivalent coefficient of friction in case of block brake with long shoe is denoted by μ[4Sinθ/2θ+sin4θ].

Solution:

Explanation: μ[4Sinθ/2θ+sin2θ].

QUESTION: 7

In pivoted block brakes, moment of frictional force about pivot is non zero.

Solution:

Explanation: Pivot point is selected such that moment of frictional force about pivot point is zero.

QUESTION: 8

Shoe is constrained to move towards the drum to compensate for the moment acting.

Solution:

Explanation: It compensates for the wear which is constant for all points.

QUESTION: 9

A pivoted double block brake has a drum radius of 280mm with two shoes subtending an angle of 100⁰. Calculate the distance of pivot from axis of drum.

Solution:

Explanation: h=4Rsinθ/2θ+sin2θwhere θ=100/2.

QUESTION: 10

A pivoted double block brake has a drum radius of 280mm with two shoes subtending an angle of 100⁰. Maximum pressure intensity is 0.5N/mm². If the width of friction lining is 90mm, find the torque capacity f each shoe. Assume coefficient of friction as 0.2.

Solution:

Explanation: M=2μR²wpsinθ.