⚙️ 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

What will happen to orbital speed of a satellite if its orbital radius (R+h) is half of its initial value?Answer: Increase √2 times The correct relation between coefficient of Linear and coefficient of volume expansion is?Answer: β = 3α What will be the pressure on floor, of a girl has weight of 392 N ans wearing heel shoes with an area 0.0001m²?Answer: 3.92 MPa What is the relation between work (W) done and torque (τ) in rotational motion?Answer: W=τdθ If an object is placed at principal focus of convex lens it's image will be at ____?Answer: di = (infinity) In a telescope, the magnification is 5 and the distance between the objective and eyepiece is 24 cm. What are the focal lengths of the objective and eyepiece lenses?Answer: 20 cm and 4 cm According to equation of continuity A1V1 = A2V2 = constant. The constant is equal to the ______?Answer: Volume flow rate A cable breaks if stretched by more than 2mm. It is cut into two equal parts. By how much either part can be stretched without breaking?Answer: 2 mm The amount of the energy equivalent is 1 a.m.u is?Answer: 931 MeV If the room is air tight the heat absorption at constant volume is 1.4 × 10⁶ J and delivers the power of 2KW, the time to provide the energy is _____?Answer: 700s A body is said to have uniform velocity, which of the following relations will hold for average and instantaneous velocities?Answer: Average velocity is equal to instantaneous velocity A car is moving at 20ms-¹ along a straight road and sounds its horn at 500 Hz. What frequency do you hear aa the car is approaching you? (Use speed of sound = 340ms-¹)Answer: 531 Hz The velocity at which relativistic length of a body reduces to half or its proper length is ____?Answer: v = √3/2c The relation between total time of flight and height of projectile is _____?Answer: H = gT²/8 If a sound note has intensity (I), equals to faintest audible sound (I₀), then will be it's sound level?Answer: 0 dB The ratio of M.O.I of thin walled cylinder to M.O.I of solid sphere is _____?Answer: 5/2 The sample of polonium - 218 has original mass of 160 micrograms. How much of this sample will be left after three half lives?Answer: 20 Micrograms NH4Cl contains _____?Answer: All of these An alkene "X" on ozonolysis gives CH3CH2COCH3 and CH3CHO. The IUPAC name of X is?Answer: 3-Methyl-2-Pentene Calcium propionate and calcium acetate on heating together produce ______?Answer: Ethyl methyl ketone The gases used in different types of welding would include:Answer: Oxygen and acetylene A hand drill consists of two mutually perpendicular ____?Answer: Gears Machines that function on the combine motion of pulley and gear system is/are ______?Answer: All of these A mechanical appliance which can work on _____ principle is a hydraulic system.Answer: Pascal's The torque in a uniformly rotating fan having blade of length 0.5m is ______?Answer: 0 Nm The angle at which x and y components of force are equal ______?Answer: 45° Young modulus is measured in units of ______?Answer: Pa The perception of sound intensity is ______?Answer: Loudness What is the kinetic energy of a bullet of mass 0.03 kg traveling at a speed of 400 m/s?Answer: 2400 J When is the restoring force minimum in simple harmonic motion (SHM), given F = -kx?Answer: At equilibrium (mid) position