Recent questions in Heat Transfer / GO Mechanical

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GATE Mechanical 2014 Set 1 | Question: 48
A reversible heat engine receives $2$ $kJ$ of heat from a reservoir at $1000$ $K$ and a certain amount of heat from a reservoir at $800$ $K$. It rejects $1$ $kJ$ of heat to a reservoir at $400$ $K$. The net work output (in $kJ$) of the cycle is $0.8$ $1.0$ $1.4$ $2.0$

A reversible heat engine receives $2$ $kJ$ of heat from a reservoir at $1000$ $K$ and a certain amount of heat from a reservoir at $800$ $K$. It rejects $1$ $kJ$ of heat ...

Arjun

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Arjun asked Feb 19, 2017

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GATE Mechanical 2014 Set 1 | Question: 47
In an air-standard Otto cycle, air is supplied at $0.1$ $MPa$ and $308$ $K$. The ratio of the specific heats $(γ)$ and the specific gas constant $(R)$ of air are $1.4$ and $288.8$ $J/kg.K$, respectively. If the compression ratio is $8$ and the maximum temperature in the cycle is $2660$ $K$, the heat (in $kJ/kg$) supplied to the engine is _______

In an air-standard Otto cycle, air is supplied at $0.1$ $MPa$ and $308$ $K$. The ratio of the specific heats $(γ)$ and the specific gas constant $(R)$ of air are $1.4$ a...

Arjun

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Arjun asked Feb 19, 2017

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GATE Mechanical 2014 Set 1 | Question: 42
Consider one dimensional steady state heat conduction across a wall (as shown in figure below) of thickness $30$ $mm$ and thermal conductivity $15$ $W/m.K$. At $x$ = $0$, a constant heat flux, ${q}''$ = $1 105$ $W$/$m^2$ is applied. On ... $250$ $W$/$m^2.K$. The temperature (in $°C$), at $x$ = $0$ is _______

Consider one dimensional steady state heat conduction across a wall (as shown in figure below) of thickness $30$ $mm$ and thermal conductivity $15$ $W/m.K$. At $x$ = $0$,...

Arjun

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Arjun asked Feb 19, 2017

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GATE Mechanical 2014 Set 1 | Question: 41
$1.5$ kg of water is in saturated liquid state at $2$ bar $(vf = 0.001061 \: m^3/kg, uf = 504.0 \: kJ/kg,$ $hf = 505 kJ/kg$). Heat is added in a constant pressure process till the temperature of water reaches $400^ \circ C (v = 1.5493 \: m^3/kg, u = 2967.0 kJ/kg,$ $h = 3277.0 \: kJ/kg)$. The heat added (in $kJ$) in the process is _______

$1.5$ kg of water is in saturated liquid state at $2$ bar $(vf = 0.001061 \: m^3/kg, uf = 504.0 \: kJ/kg,$ $hf = 505 kJ/kg$). Heat is added in a constant pressure proces...

Arjun

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Arjun asked Feb 19, 2017

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GATE Mechanical 2014 Set 1 | Question: 14
Consider a two-dimensional laminar flow over a long cylinder as shown in the figure below. The free stream velocity is $U_\infty$ and the free stream temperature $T_\infty$ is lower than the cylinder surface temperature $T_S$. The local heat transfer coefficient is minimum at point $1$ $2$ $3$ $4$

Consider a two-dimensional laminar flow over a long cylinder as shown in the figure below.The free stream velocity is $U_\infty$ and the free stream temperature $T_\infty...

Arjun

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Arjun asked Feb 19, 2017

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GATE ME 2013 | Question: 51
Water (specific heat, $c_p$ = $4.18$ $kJ$/$kgK$) enters a pipe at a rate of $0.01$ $kg$/$s$ and a temperature of $20^0$ $C$.The pipe, of diameter $50$ $mm$ and length $3$ $m$, is subjected to a wall heat flux ${q_{w}}''$ in $W$/$m^2$: ... $ $W$/$m^2$K$, the temperature in $_{}^{0}\textrm{C}$ at the inner surface of the pipe at the outlet is $71$ $76$ $79$ $81$

Water (specific heat, $c_p$ = $4.18$ $kJ$/$kgK$) enters a pipe at a rate of $0.01$ $kg$/$s$ and a temperature of $20^0$ $C$.Thepipe, of diameter $50$ $mm$ and length $3$ ...

piyag476

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piyag476 asked Feb 19, 2017

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GATE ME 2013 | Question: 50
Water (specific heat, $c_p$ = $4.18$ $kJ$/$kgK$) enters a pipe at a rate of $0.01 kg/s$ and a temperature of $20^ \circ C$.The pipe, of diameter $50$ $mm$ and length $3$ $m$, is subjected to a wall heat flux ${q_{w}}''$ in $W$ ... ($x = 0$ at the inlet), the bulk mean temperature of the water leaving the pipe in $^\circ \textrm{C}$ is $42$ $62$ $74$ $104$

Water (specific heat, $c_p$ = $4.18$ $kJ$/$kgK$) enters a pipe at a rate of $0.01 kg/s$ and a temperature of $20^ \circ C$.The pipe, of diameter $50$ $mm$ and length $3$ ...

piyag476

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piyag476 asked Feb 19, 2017

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GATE ME 2013 | Question: 44
The pressure, temperature and velocity of air flowing in a pipe are $5$ $bar$, $500$ $K$ and $50$ $m$/$s$, respectively. The specific heats of air at constant pressure and at constant volume are $1.005$ $kJ$/$kgK$ and $0.718$ $kJ$/$kgK$, respectively. ... $bar$ and $300$ $K$, respectively, the available energy in $kJ$/$kg$ of the air stream is $170$ $187$ $191$ $213$

The pressure, temperature and velocity of air flowing in a pipe are $5$ $bar$, $500$ $K$ and $50$ $m$/$s$, respectively. The specific heats of air at constant pressure an...

piyag476

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piyag476 asked Feb 19, 2017

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GATE ME 2013 | Question: 42
Two large diffuse gray parallel plates, separated by a small distance, have surface temperatures of $400$ $K$ and $300$ $K$. If the emissivities of the surfaces are $0.8$ and the Stefan-Boltzmann constant is $5.67$ × $10^{-8}$ $W$/$m^2$ $K^4$, the net radiation heat exchange rate in $kW$/$m^2$ between the two plates is $0.66$ $0.79$ $0.99$ $3.96$

Two large diffuse gray parallel plates, separated by a small distance, have surface temperatures of $400$ $K$ and $300$ $K$. If the emissivities of the surfaces are $0.8$...

piyag476

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piyag476 asked Feb 19, 2017

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GATE ME 2013 | Question: 30
A steel ball of diameter $60$ $mm$ is initially in thermal equilibrium at $1030^0C$ in a furnace. It is suddenly removed from the furnace and cooled in ambient air at $30^0C$, with convective heat transfer coefficient $h = 20 W/m^2K$. The thermo-physical ... required in seconds to cool the steel ball in air from $1030^0C$ to $430^0C$ is $519$ $931$ $1195$ $2144$

A steel ball of diameter $60$ $mm$ is initially in thermal equilibrium at $1030^0C$ in a furnace. It is suddenly removed from the furnace and cooled in ambient air at $30...

piyag476

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piyag476 asked Feb 19, 2017

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GATE ME 2013 | Question: 19
Consider one-dimensional steady state heat conduction along $x$-axis ($0 \leq x \leq L$), through a planewall with the boundary surfaces ($x = 0$ and $x = L$) maintained at temperatures of $0^{\circ} C$ and $100^{\circ}C$. ... . The temperature distribution is linear within the wall. The temperature distribution is symmetric about the mid-plane of the wall.

Consider one-dimensional steady state heat conduction along $x$-axis ($0 \leq x \leq L$), through a planewall with the boundary surfaces ($x = 0$ and $x = L$) maintained...

piyag476

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piyag476 asked Feb 19, 2017

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GATE ME 2013 | Question: 9
Consider one-dimensional steady state heat conduction, without heat generation, in a plane wall; with boundary conditions as shown in the figure below. The conductivity of the wall is given by $k$ = $k_0$ + $bT$ ; where $k_0$ and $b$ are positive ... $x$ increases, the temperature gradient ( $dT$/ $dx$ ) will remain constant be zero increase decrease

Consider one-dimensional steady state heat conduction, without heat generation, in a plane wall; with boundary conditions as shown in the figure below. The conductivity o...

piyag476

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piyag476 asked Feb 19, 2017

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GATE ME 2013 | Question: 8
The pressure, dry bulb temperature and relative humidity of air in a room are $1$ bar, $30^{\circ} C$ and $70\%$, respectively. If the saturated steam pressure at $30^{\circ} C$ is $4.25$ $kPa$, the specific humidity of the room air in $kg$ water $\text{vapour/kg}$ dry air is $0.0083$ $0.0101$ $0.0191$ $0.0232$

The pressure, dry bulb temperature and relative humidity of air in a room are $1$ bar, $30^{\circ} C$ and $70\%$, respectively. If the saturated steam pressure at $30^{\c...

piyag476

1.4k points

piyag476 asked Feb 19, 2017