Quiz: Mechanical Engineering
Each question carries 1 mark
Negative marking: 1/4 mark
Time: 8 Minutes
Q1. The instrument preferred in the measurement of highly fluctuating velocities in air flows is
(a) Pitot-static tube
(b) Propeller type anemometer
(c) Three cup anemometer
(d) Hot wire anemometer
Q2. For an inclined plane submerged in a liquid, the centre of pressure on one side of the plane will be
(a) above the top edge of the area
(b) vertically below the center of gravity
(c) below the center of gravity
(d) in the same horizontal plane as the center of gravity
Q3. The mechanism used to overcome a large resistance of a member with a small driving force is known as
(a) Indexing mechanism
(b) Snap action mechanism
(c) Whitworth mechanism
(d)Crank rocker mechanism
Q4. Toggle mechanism have following applications except
(a) Stone crushers
(b) Gear cutting
(c) Embossing presses
Q5. Mean effective pressure at a given compression ratio is maximum when the fuel-air ratio is
(a) higher than stoichiometric
(b) lower than stoichiometric
(c) equal to stoichiometric
(d) none of the above
Q6. At breakeven point:
(a) Sales revenue > total cost
(b) Sales revenue = total cost
(c) Sales revenue < total cost
(d) None of the above
S1. Ans (d)
Sol. Hot wire anemometer is used for the measurement of highly fluctuating velocities in air. This can be done by measuring the heat loss of the wire which is placed in the fluid stream. The wire is heated by electrical current. The hot wire when placed in the stream of the fluid, in that case, the heat is transferred from wire to fluid, and hence the temperature of wire reduces. The resistance of wire measures the flow rate of the fluid which is the function of heat loss from the wire and change in the resistance of wire.
S2. Ans (c)
Sol. For an inclined plane submerged in a liquid, the center of pressure is below the center of gravity.
S3. Ans (b)
Sol. It is a quick-break mechanism without intermediate state. Switching is obtained by the deformation of a spring or moving contact when the switch is operated.
S4. Ans (b)
Sol. Stone crushers, embossing presses and switches works on toggle mechanism. Mechanical advantage of toggle mechanism is infinite or very large.
S5. Ans (b)
Sol. Maximum mean effective pressure is obtained at slightly leaner mixture or lower than stoichiometric mixture.
Sol. Breakeven point- The breakeven point is the level of production at which the costs of production equal the revenues for a product. At breakeven point, profit will be zero even there is no loss.
Which means sales revenue is equal to total cost.
Sales revenue = total cost