A fin of length l protrudes from a surface held at temperature T0; it being higher than the ambient temperature Ta. The heat dissipation from the free end of the fin is stated to be negligibly small. What is the temperature gradient \((\frac {dT}{dx})_{x=L}\) at the tip of the fin?
1
Zero
2
\(\frac {T_0 -T_l}{l}\)
3
h(T0 - Ta)
4
\(\frac {T_l -T_a}{T_0 -T_a}\)