Engineering Questions with Answers - Multiple Choice Questions
Machine Dynamics MCQ – Steam Engine Valves and Reversing Gears
1 - Question
In a steam engine, the distance by which the outer edge of the D-slide valve overlaps the steam port is called
a) lead
b) steam lap
c) exhaust lap
d) none of the mentioned
View Answer
Answer: b
Explanation: Steam lap is the distance by which the outer edge of the D-slide valve overlaps the steam port.
2 - Question
In a steam engine, the distance by which the inner edge of the D-slide valve overlaps the steam port is called lead.
a) True
b) False
View Answer
Answer: b
Explanation: In actual practise, the displacement of the D-slide valve is greater than the steam lap by a distance known as lead of the valve.
3 - Question
The displacement of the D-slide valve is ______________ the steam lap by a distance known as lead of the valve.
a) greater than
b) less than
c) equal to
d) none of the mentioned
View Answer
Answer: a
Explanation: In actual practise, the displacement of the D-slide valve is greater than the steam lap by a distance known as lead of the valve.
4 - Question
The D-slide valve is also known as
a) inside admission valve
b) outside admission valve
c) piston slide valve
d) none of the mentioned
View Answer
Answer: b
Explanation: Since the steam is admitted from outside the steam chest, therefore, D-slide valve is also known as outside admission valve.
5 - Question
The piston slide valve is an inside admission valve.
a) True
b) False
View Answer
Answer: a
Explanation: Since the steam enters from the inside of the two pistons, therefore, the piston valve is also known as inside admission valve.
6 - Question
The distance by which the _____________ of the D-slide valve overlaps the steam port is called exhaust lap.
a) inner edge
b) outer edge
c) centre edge
d) none of the mentioned
View Answer
Answer: a
Explanation: Steam lap or exhaust lap is the distance by which the outer edge of the D-slide valve overlaps the steam port.
7 - Question
Which of the following statement is correct?
a) The power absorbed in operating the piston valve is less than D-slide valve.
b) The wear of the piston valve is less than the wear of the D-slide valve.
c) The D-slide valve is also called outside admission valve.
d) all of the mentioned
View Answer
Answer: d
Explanation: All the statements are correct.
8 - Question
The distance moved by the valve from one end to the other end is called valve travel.
a) True
b) False
View Answer
Answer: a
Explanation: Valve travel is the distance moved by the valve from one end to the other end.
9 - Question
The throw of the eccentric is equal of the valve travel.
a) True
b) False
View Answer
Answer: b
Explanation: The throw of the eccentric is equal to half of the valve travel.
10 - Question
In a steam engine, one method of obtaining the earlier cut-off with a simple slide valve is by increasing the angle of advance of the eccentric while the throw of the eccentric, steam lap and exhaust lap are kept constant. The method will
a) cause withdrawing or throttling of steam
b) reduce length of effective stroke of piston
c) reduce maximum opening opening of port to steam
d) all of the mentioned
View Answer
Answer: b
Explanation: In a steam engine, one method of obtaining the earlier cut-off with a simple slide valve is by increasing the angle of advance of the eccentric while the throw of the eccentric, steam lap and exhaust lap are kept constant. The method will reduce length of effective stroke of piston.
In a steam engine, one method of obtaining the earlier cut-off with a simple slide valve may be obtained by increasing the angle of advance of the eccentric but reducing the throw of the eccentric and keeping the steam lap and exhaust lap constant. The method will cause withdrawing or throttling of steam.