** Mechanical
Engineering Written Exam Questions (Part-1)**

➤ Show
that, **specific speed of pump is a
dimensionless number**.

➤ Draw
**P-V & T-S diagram of Otto & Diesel
cycle** and write down the corresponding process name.

➤ Find
the **absolute pressure in Pa of 100 mm
mercury vacuum pressure**.

**We Know that,**

Absolute Pressure = atmospheric pressure – vacuum pressure

= 760 – 100 = 660 mm of mercury

We also know,

**P = h**

**ρ**

**g**

= 0.660 x 13600 x 9.81

=

**88054.56 Pa**

P = Absolute pressure, Pa

h = Manometer height, m

ρ = Density of mercury = 13600 Kg/m

^{3}

^{2}

^{}

➤ **Draw block diagram &
T-S diagram for gas-steam combine cycle power plant. (For more details, click here)**

➤ A
4 cylinder petrol engine has developed MEP=650 KPa, its engine diameter is 80
mm, stroke length is 100 mm, speed 3000 rpm. **Find engine power in KW**?

➤ For
counter flow heat exchanger T_{h1}=160^{o}C, T_{h2}=125^{o}C,
T_{c1}=20^{o}C, T_{c2}=80^{o}C, **Draw temperature distribution curve**. **Also find arithmetic mean temperature
difference & logarithmic mean temperature difference**.

➤ A
wire has got diameter of 20 mm, if heat transfer co-efficient is 20 W/m^{2}.K
and thermal conductivity is 0.5 W/m.k. **Then
find the distance at which maximum heat dissipation will occur.**

➤ A
1.5m x 1.5m x 2m tank is kept at 11 m above from the ground. If a pump
installed on ground having efficiency of 60% can fill the tank in 30 minutes, then
**find the required pump power**.

➤ Engine
power developed 40 KW, solid shafts rpm 200, if the shaft diameter 40 mm then, **find maximum torsional stress developer in
the shaft**.

➤ **Find the deflection of a
solid circular steel bar**
having load 500 Kg, length 2.5 meter, diameter 60 mm & E=200 GPa.

➤ A
60 mm metal ball at 220^{o}C is being cooled by air jet of 20^{o}C,
heat transfer co-efficient 200 W/m.k & 100 W/m^{2}.K, if the
specific heat of the metal ball 400 J/Kg.K, density 9000 Kg/m^{3}, **Find the temperature of the ball after 90
sec**.

➤ An
aeroplane makes a complete half circle of 50 meters radius, towards left, when
flying at 200 Km/hr. the rotary engine and the propeller of the plane has a
mass of 400 Kg and a radius of gyration of 0.3 meter. The engine rotates at
2400 rpm clockwise when viewed from the rear. **Find the gyroscopic couple on the aircraft**.

➤ In
a vapor compression refrigeration cycle inlet condenser enthalpy is 283 KJ/Kg,
exit condenser enthalpy is 116 KJ/Kg, and exit evaporator enthalpy is 232
KJ/Kg, **Find COP**.

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