A portable heated wax-sealing pen is used to apply decorative wax seals to craft packaging. The DC electrical supply to the micro-heater element in the pen has an e.m.f., ε\varepsilonε, of 18 V18\text{ V}18 V. The electrical power rating of the heater element is 54 W54\text{ W}54 W.
Calculate the electrical resistance, RRR, of the micro-heater element.
The specific latent heat of fusion of the sealing wax is 1.8×105 J kg−11.8 \times 10^5\text{ J kg}^{-1}1.8×105 J kg−1 and its melting point is 65∘C65^\circ\text{C}65∘C.
Define specific latent heat of fusion.
Calculate the maximum mass mmm of sealing wax that the heater could melt in 2.5 minutes2.5\text{ minutes}2.5 minutes.
Explain why the melting process is slower in practice than your answer to (ii) suggests.
