# Basic Conduction Exercise

1. In the equation of Fourier law of heat conduction, what does the negative sign in the formula take care of

1. Decreasing temperature along the direction of increasing thickness
2. Increasing temperature along the direction of increasing thickness
3. Constant temperature along the direction with constant thickness
4. All of the above
Answer

2. A steel plate of k=50W/mK and thickness 10cm passes a heat flux by conduction of 25kW/m2 . If the temperature of hot surface of plate is 100 ͦC, then what is the temperature of the cooler side of plate?

1. 30 ͦC
2. 40 ͦC
3. 50 ͦC
4. 60 ͦC
Answer

3. Two walls of same thickness and cross sectional area have thermal conductivity in ratio of 1:2. If the same temperature difference is maintained across the two faces of both the walls, what is the ratio of heat flow

1. ½
2. 1
3. 2
4. 4
Answer

4. A wall of thickness 10cm conducts heat at rate of 30W/m2 when the temperature difference across wall is 10K. What is thermal conductivity (W/mK)

1. 0.3
2. 3
3. 0.03
4. 0.1
Answer