1) A piston has allowable tensile stress of 50 N/mm2 and has bore diameter 150 mm. Considering strength of piston, what will be the thickness of piston head if maximum pressure of 10 N/mm2 acts on it?
a. 29 mm
b. 35 mm
c. 53 mm
d. Insufficient data
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Answer
Explanation
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ANSWER: 29 mm
Explanation:
No explanation is available for this question!
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2) A piston made of gray cast iron has piston head thickness of 20 mm. What will be thickness of piston barrel under piston rings if it has allowable tensile stress of 30 N/mm2? ( Bore diameter = 50 mm & Pmax =15 N/mm2)
a. 10 mm
b. 20 mm
c. 30 mm
d. Insufficient data
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Answer
Explanation
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ANSWER: 20 mm
Explanation:
No explanation is available for this question!
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3) What is the function of gudgeon pin?
a. Acts as stiffeners
b. Supports piston head
c. Connects piston to connecting rod
d. All of the above
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Answer
Explanation
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ANSWER: Connects piston to connecting rod
Explanation:
No explanation is available for this question!
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4) Which of the following parts of piston act as bearing for connecting rod side thrust?
a. Reinforcing ribs
b. Piston barrel
c. Piston gudgeon
d. Piston skirt
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Answer
Explanation
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ANSWER: Piston skirt
Explanation:
No explanation is available for this question!
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5) Single cylinder four stroke engine has brake power of 8 kW and brake mean effective pressure of 0.55 Mpa. What is the length of cylinder which is 1.2 times of bore diameter? (n = 3000 rpm)
a. 110 mm
b. 103 mm
c. 70 mm
d. 65 mm
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Answer
Explanation
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ANSWER: 103 mm
Explanation:
No explanation is available for this question!
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6) Which stress is induced in cylinder wall due to side thrust of the piston?
a. Axial stress
b. Circumferential stress
c. Longitudinal stress
d. Bending stress
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Answer
Explanation
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ANSWER: Bending stress
Explanation:
No explanation is available for this question!
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7) Thermal stress in cylinder liners can be reduced by _______
a. increasing the wall thickness of cylinder liner
b. increasing velocity of flowing water through jacket
c. both a. and b.
d. none of the above
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Answer
Explanation
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ANSWER: increasing velocity of flowing water through jacket
Explanation:
No explanation is available for this question!
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8) Which of the following materials are used for cylinder liners?
a. Alloy cast iron
b. Grey cast iron
c. Both a. and b.
d. None of the above
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Answer
Explanation
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ANSWER: Both a. and b.
Explanation:
No explanation is available for this question!
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9) Which type of cylinder liners are used in engines having bore diameter more than 125 mm?
a. Dry liners
b. Wet liners
c. Both a. and b.
d. None of the above
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Answer
Explanation
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ANSWER: Wet liners
Explanation:
No explanation is available for this question!
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10) Which of the following statements is/are false if separate cylinder liner is pressed inside the cylinder of large engines?
a. Easy replacement of liner in case of wear and tear
b. Cheap grade material cannot be used for jacket
c. Liner is to be made of heat resistant cast iron
d. None of the above
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Answer
Explanation
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ANSWER: Cheap grade material cannot be used for jacket
Explanation:
No explanation is available for this question!
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