$10$:$09$

$4$G

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YIC$/$MCET

$14$ September $2024$

Page $2$ of $4$

Q$1.$ Choose the correct answer:

The specific heat of a material is given in a strange unit to be c $53\mathrm{.}60k\frac{J}{k}g*8F.$ The specific heat of this material in the SI units of $k\frac{J}{k}g*C$ is

$($a$)2\mathrm{.}00k\frac{J}{k}g*C$

$($b$)3\mathrm{.}20k\frac{J}{k}g*C$

$($c$)3\mathrm{.}60k\frac{J}{k}gC$

$($d$)4\mathrm{.}80k\frac{J}{k}gC$

$($e$)6\mathrm{.}48k\frac{J}{k}gC$

A $3-m3$ rigid tank contains nitrogen gas at $500$ kPa and $300$ K $.$ Now heat is transferred to the nitrogen in the tank and the pressure of nitrogen rises to $800$ kPa $.$ The work done during this process is

$($a$)500$ kJ

$($b$)1500$ kJ

$($c$)0$ kJ

$($d$)900$ kJ

$($e$)2400$ kJ

A $0\mathrm{.}5-m3$ rigid tank contains nitrogen gas at $600$ kPa and $300$ K $.$ Now the gas is compressed isothermally to a volume of $0\mathrm{.}1m3.$ The work done on the gas during this compression process is:

$($a$)720$ kJ

$($b$)483$ kJ

$($c$)240$ kJ

$($d$)175$ kJ

$($c$)143$ kJ

A well$-$sealed room contains $60$ kg of air at $200$ kPa and $25C.$ Now solar energy enters the room at an average rate of $0\mathrm{.}8k\frac{J}{s}$ while a $120-W$ fan is turned on to circulate the air in the room. If heat transfer through the walls is negligible, the air temperature in the room in $30$ min will be

$($a$)25\mathrm{.}6C$

$($b$)49\mathrm{.}8C$

$($c$)53\mathrm{.}4C$

$($d$)52\mathrm{.}5C$

$($e$)63\mathrm{.}4C$

A $2-kW$ baseboard electric resistance heater in a vacant room is turned on and kept on for $15$ min. The mass of the air in the room is $75$ kg $,$ and the room is tightly sealed so that no air can leak in or out. The temperature rise of air at the end of $15$ min is

$($a$)8\mathrm{.}5C$

$($b$)12\mathrm{.}4C$

$($c$)24\mathrm{.}0C$

$($d$)33\mathrm{.}4C$

$($e$)54\mathrm{.}8C$

Steam is compressed by an adiabatic compressor from $0\mathrm{.}2$ MPa and $150C$ to $2\mathrm{.}5$ MPa and $250C$ at a rate of $1,30k\frac{g}{s}.$ The power input to the compressor is

$($a$)144$ kW

$($b$)234$ kW

$($c$)438$ kW

$($d$)717$ kW

$($c$)901$ kW

Steam enters a diffuser steadily at $0\mathrm{.}5$MPa,$300C,$ and $122\frac{m}{s}$ at a rate of $3\mathrm{.}5k\frac{g}{s}.$ The inlet area of the diffuser is

$($a$)15c{m}^2$

$($b$)50c{m}^2$

$($c$)105c{m}^2$

$($d$)150c{m}^2$

$($c$)190c{m}^2$