Quiz: Mechanical Engineering
Topic: Production Engineering
Each question carries 2 mark
Negative marking: 1/3 mark
Time: 10 Minutes
Q1. What is the type of welding defect is caused due to stresses on heating and cooling called?
(a) Incomplete penetration
(b) Shrinkage void
(c) Slag entrapment
(d) Incomplete fusion
Q2. What is the type of welding defect caused due to poor deposition of weld rod is called?
Q3. A lead-screw with half nuts in a lathe, free to rotate in both directions has
(b) Whitworth threads
(c) Buttress threads
(d) Acme threads
Q4. While current is shut down in the welding circuit, what kind of voltage exists between the output terminals of the welding machine?
(b) Open air cut voltage
Q5. Two plates of the same metal having equal thickness are to be butt welded with electric arc. When the plate thickness changes, welding is achieved by
(a) Adjusting the current
(b) Adjusting the duration of current
(c) Changing the electrode size
(d) Changing the electrode coating
Q6. A twist drill is a
(a) Side cutting tool
(b) Front cutting tool
(c) End cutting tool
(d) None of these
Q7. While cutting helical gears on a non-differential gear hobber, the feed change gear ratio is
(a) Independent of index change gear ratio
(b) Dependent on speed change gear ratio
(c) Interrelated to index change gear ratio
(d) Independent of speed and index change gear ratio
Q8. The drill spindles are provided with standard taper known as
(a) Morse taper
(b) Seller’s taper
(c) Chapman taper
(d) Brown and sharpe taper
Q9. In centerless grinders, the regulating wheel is inclined at
(a) 0° to 8°
(b) 9° to 15°
(c) 16° to 20°
(d) 21° to 25°
Q10. The grinding of long, slender shafts or bars is usually done by
(a) In-Feed grinding
(b) Through feed grinding
(c) End feed grinding
(d) Any of these
Q11. A bottoming tap has
(a) Its end tapered for about three or four threads
(b) Its end tapered for about eight or ten threads
(c) Full threads for the whole of its length
(d) None of the above
Q12. The rear tooth of broach
(a) Perform burnishing operation
(b) Remove minimum metal
(c) Remove maximum metal
(d) remove no metal
Q13. The lathe spindle are usually made hollow and provided with
(a) Internal taper
(b) External taper
(c) Internal and external taper
(d) No taper
Q14. A push broach as compared to pull broach
1. Has less no. of teeth
2. Is short and stocky
3. Remove less material for each pass of tool
Which of the following statements are correct?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1,2 and 3 only
Q15. The machining of titanium is difficult due to
(a) High thermal conductivity of titanium
(b) Chemical reaction between tool and workpiece
(c) low tool chip contact area
(d) None of these
Soln. Slag entrapment (inclusions) welding defect is caused due to stresses on heating and cooling.
Soln. Porosity is a welding defect caused due to poor deposition of weld rod.
Soln. A lead-screw with half nuts in a lathe, free to rotate in both directions had Acme threads. When it is used in conjunction with a split nut, as on the lead screw of a lathe, the tapered sides of the threads facilitate ready to engagement and disengagement of the halves of the nut when required.
Soln. Open air cut voltage is the voltage between the output terminals of the welding machine when no current is flowing in the welding circuit.
Soln. Electric arc welding is a welding process wherein coalescence is produced by heating with an arc, with or without the use of filler metals. No filler metal is used in butt weld. So, when the plate thickness changes, welding is achieved by changing the electrode size.
Soln. Twist drill is a rotating cutting tool, used for cutting holes in rigid materials which is consists of an essentially conical point, relieved and fluted to form cutting lips, and spiral flutes which direct the chips away from the lips and toward ejection from the hole
Soln. The differential mechanism is used for cutting of helical gears. The differential mechanism has no connection to the cutting speed. Feed change gear ratio is inter-related to index change gear ratio.
Soln. Morse taper is provided on all drilling accessories, inside drilling machine spindle, lathe tail stock, lathe turret and lathe centres.
Soln. In centerless grinding, the workpiece is held between two grinding wheels, rotating in the same direction at different speeds. One grinding wheel is on a fixed axis and rotates so that the force applied to the workpiece is directed downward.
Soln. Through-feed grinding is a type of centerless grinding. During this process, the workpiece passes through the machine itself. It proves to be an effective option for single-size diameter parts anywhere from a small dowel pin to a 16” shaft
Soln. Bottoming tap is designed with a 1 to 2 thread chamfer, is made with just enough chamfer for starting in the hole; as the name implies, it is designed to thread blind holes to the bottom.
Soln. The total material removed in a single pair of the broach is the cumulative result of all the teeth in the tool in action (it is not necessary that all the teeth available in the broach in action at a time) but maximum material is removed by rear tooth.
Soln. The lathe spindles are usually made hollow and provided with Internal taper. Lathe spindles are used for machine-cutting of workpieces. It can also be referred to as workpiece spindles as the workpiece is clamped via the chuck of the lathe spindle
Soln. Machining of titanium is very difficult due to low chip tool contact area.