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Standard VII

Physics

Conduction

The area of g...

Question

The area of glass of a window of a room is $10$ $m^{2}$ and thickness is $2$ mm. The outer and inner temperatures are 40 $^{o}$ C and 20 $^{o}$ C respectively. Thermal conductivity of glass in S.I unit is $0.2$ . The heat flowing in the room per second will be :

3 \times 10

^{4}

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2 \times 10

^{4}

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30

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45

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Solution

The correct option is B $2 \times 10$ $^{4}$ J
$K = 0.2$
$A = 10$
$θ_{1} = 40; θ_{2} = 20$
$t = 1; l = 0.002$

Heat flowing in the room per second will be

$Q = K A \frac{d T}{d x}$
$Q = \frac{0.2 \times 10 \times 20 \times 1}{0.002}$
$Q = 20000 J$

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The area of glass of a window of a room is 10 m2 and thickness is 2mm. The outer and inner temperatures are 40oC and 20oC respectively. Thermal conductivity of glass in S.I unit is 0.2. The heat flowing in the room per second will be :

The correct option is B 2×104 JK=0.2A=10θ1=40; θ2=20t=1; l=0.002Heat flowing in the room per second will beQ=KAdTdxQ=0.2×10×20×10.002 Q=20000J

The area of glass of a window of a room is $10$ $m^{2}$ and thickness is $2$ mm. The outer and inner temperatures are 40 $^{o}$ C and 20 $^{o}$ C respectively. Thermal conductivity of glass in S.I unit is $0.2$ . The heat flowing in the room per second will be :

The correct option is B $2 \times 10$ $^{4}$ J
$K = 0.2$
$A = 10$
$θ_{1} = 40; θ_{2} = 20$
$t = 1; l = 0.002$

Heat flowing in the room per second will be

$Q = K A \frac{d T}{d x}$
$Q = \frac{0.2 \times 10 \times 20 \times 1}{0.002}$
$Q = 20000 J$