⚙️ Mechanical Eng Solved MCQs with Answers

Practice 934 approved ⚙️ Mechanical Eng questions with verified answers from the 🛠️ Engineering Essentials subject for Pakistan exams.

934 solved MCQs

Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its C.G. and parallel to the base, isAnswer: bh³/36 The condition that causes vapour locking in a brake system isAnswer: overheating of the fluid due to frequent brake application The portion of a crankshaft which rests on cylinder block is called main journal.Answer: Yes A baffle plate is fitted inside the oil pan to prevent the oil from splashing when it is subjected to vibration and other movement during vehicle operation.Answer: True The motion of the cam is transferred to the valves throughAnswer: rocker arms Which of the following is an equation of linear motion?(where, u and v = Initial and final velocity of the body, a = Acceleration of the body, and s = Displacement of the body in time t seconds.)Answer: all of these Which of the following symptom is caused as a result of brake disc run out ?Answer: Judder during braking If the engine coolant leaks into the engine oil, then engine oilAnswer: appears milky The function of an alternator in an automobile is toAnswer: continually recharge the battery A clutch is usually designed to transmit maximum torque which isAnswer: 150 per cent of the maximum engine torque If a number of forces are acting at a point, theirresultant will be inclined at an angle θ with the horizontal, such thatAnswer: tan θ = ∑V/∑H What type of bearing is used for main bearings and connecting rod bearings ?Answer: Plain bearings It is necessary to maintain the valve clearances as theyAnswer: allow for lengthening of the valves owing to the heat of combustion The force required to move the body up the plane will be minimum if it makes an angle with the inclined plane __________ the angle of friction.Answer: equal to Incorrect steering axis inclination (S.A.I.) causesAnswer: poor recovery of the steering wheel after making a turn In a unit type body (frameless body) design, the sheet metal parts are welded together, forming a frame work to which outer skin is attached.Answer: True The total time taken by a projectile to reach maximum height and to return back to the ground, is known as time of flight.Answer: Yes The torque available at the contact between driving wheels and road is known asAnswer: tractive effort A traction control system (TCS) in automobiles controls theAnswer: torque that is transmitted by the tyres to the road surface In radial tyresAnswer: all plies run parallel to one another and vertical to tyre bead The oil pump is driven by theAnswer: crankshaft directly In a spark plug, when the temperature of the central electrode exceeds a certain temperature, any carbon that has adhered will be burnt off, and the temperature at which this burning off carbon starts is referred to as the self cleaning temperature.Answer: Correct The flywheel and the pressure plate bind the clutch disc between them so that the engine and the transmission can be engaged.Answer: Yes The vehicle ride will be comfortable ifAnswer: unsprung mass is kept minimum The range of a projectile is maximum, when the angle of projection isAnswer: 45° The main function of intake manifold is that itAnswer: distributes intake air equally to the cylinders The mechanical advantage of a lifting machine is the ratio ofAnswer: load lifted to the effort applied Positive camber is used to compensate for wheels tilting inward due to the weight of the vehicle.Answer: Yes Static friction is always __________ dynamic friction.Answer: greater than In automobiles G.V.W. refers toAnswer: gross vehicle weight