Question 61. Find the value of corrected length for rectangular fin?
Where, b is width and t is length of the fin

Question 62. In convection from the tip what is the value of correction length?

Question 63. Let us assume there are two pieces of copper wire 0.1625 cm in diameter with a device that melts it at 195 degree Celsius. The wires are positioned vertically in air at 24 degree Celsius and the heat transfer coefficient of the wire is 17 W/ square m K. Let us say k = 335W/m K i.e. of wire. Find out the energy input?

Question 64. Which one is true for the spine?

Question 65. The figure shows a 5 cm diameter rod, 90 cm long, which is having its lower face grinded smooth. The remainder of the rod is exposed to 32 degree Celsius room air and a surface coefficient heat transfer equal to 6.8 W/m² degree exists between the rod surface and the room air. The grinder dissipates mechanical energy at the rate of 35 W. If thermal conductivity of rod material is 41.5 W/m degree, find the temperature of the rod at the point where the grinding is taking place

Question 66. If heat dissipation for one fin is given by 377.45 k J/hour, then what is the heat dissipation for 12 fins?

Question 67. If fin is sufficiently thin, so heat flows pertains to

Question 68. In order to achieve maximum heat dissipation the fin should be designed in such a way that has a

Question 69. A steel rod (k = 30 W/m degree) 1 cm in diameter and 5 cm long protrudes from a wall which is maintained at 10 degree Celsius. The rod is insulated at its tip and is exposed to an environment with h = 50 W/m² degree and t a = 30 degree Celsius. Calculate the rate of heat dissipation

Question 70. On a heat transfer surface, fins are provided to