A four-stroke engine produces one power stroke in ________ revolutions of the crankshaft.

This question was previously asked in
RRB ALP Mechanic Diesel 21 Jan 2019 Official Paper (Shift 1)
View all RRB ALP Papers >
  1. 8
  2. 6
  3. 4
  4. 2

Answer (Detailed Solution Below)

Option 4 : 2
Free
General Science for All Railway Exams Mock Test
2.1 Lakh Users
20 Questions 20 Marks 15 Mins

Detailed Solution

Download Solution PDF
Explanation:
Four-stroke engine:
  • To produce power in a four-stroke engine the following operations take place in the sequence given.
  • In this type of engine, one power stroke is obtained in two revolutions of the crankshaft.
Suction stroke:
  • The piston moves from TDC to BDC.
  • A vacuum is created inside the cylinder.
  • The inlet valve opens while the exhaust valve remains closed.
  • The charge air enters into the cylinder,
Compression stroke:
  • The inlet and exhaust valves are closed.
  • The piston moves from BDC to TDC.
  • The charge air is compressed in the cylinder & air pressure and temperature is increased.
Power stroke:
  • At the end of the compression stroke diesel fuel is injected into the hot compressed air in the combustion chamber; result burning of diesel with an explosion the gas expand and pressure develops inside the cylinder.
  • The piston moves from TDC to BDC.
  • Both the valves remain closed. Power is supplied to the fly wheel.
Exhaust stroke:
  • The inlet valve remains in closed position.
  • The exhaust valve opens, the piston moves from BDC to TDC due to the energy stored in the flywheel.
  • The burnt gases inside the cylinder go out through the exhaust valves.

F2 Vilas Engineering 9.1.2023 D15 

Latest RRB ALP Updates

Last updated on Jun 2, 2025

-> The RRB NTPC Admit Card 2025 has been released on 1st June 2025 on the official website.

-> Railway Recruitment Board activated the RRB ALP application form 2025 correction link, candidates can make the correction in the application form till 31st May 2025. 

-> The Railway Recruitment Board (RRB) has released the official RRB ALP Notification 2025 to fill 9,970 Assistant Loco Pilot posts.

-> The Railway Recruitment Board (RRB) has released the official RRB ALP Notification 2025 to fill 9,970 Assistant Loco Pilot posts.

-> The official RRB ALP Recruitment 2025 provides an overview of the vacancy, exam date, selection process, eligibility criteria and many more.

->The candidates must have passed 10th with ITI or Diploma to be eligible for this post. 

->The RRB Assistant Loco Pilot selection process comprises CBT I, CBT II, Computer Based Aptitude Test (CBAT), Document Verification, and Medical Examination.

-> This year, lakhs of aspiring candidates will take part in the recruitment process for this opportunity in Indian Railways. 

-> Serious aspirants should prepare for the exam with RRB ALP Previous Year Papers.

-> Attempt RRB ALP GK & Reasoning Free Mock Tests and RRB ALP Current Affairs Free Mock Tests here

Get Free Access Now
Hot Links: teen patti gold downloadable content teen patti master downloadable content teen patti list teen patti gold download