Reference no: EM132419069

1. Assume the muscle is 37oC and is separated from the outside air by layers of fat and skin. The layer of fat, at a particular location on the skin, is 2 mm thick and has a conductivity of 0.16 W m-1 K-1. Above this is a 1.1 mm dermis layer with a thermal conductivity of 0.53 W m-1 K-1.

Finally, the outermost epidermal layer is 0.1 mm thick with a thermal conductivity of 0.21 W m-1 K-1. How much heat is lost per unit area and unit time if the ambient air temperature is 0oC ?

2. Graphene consists of a 2D network of carbon atoms just one atom thick. This simple network of atoms results in remarkable physical properties: graphene has higher strength, better thermal conductivity, and greater intrinsic mobility than any other material known. These properties translate into huge technological potential, for example, in transparent electrodes for flatscreen TVs, in fast, energy-efficient transistors, and in ultrastrong composite materials. Hence an enormous global effort is focused on understanding and controlling graphene's properties with the aim of tailoring them for specific applications. Imagine the atoms are charged with a charge q, calculate the electric field in the center of a hexagonal unit. Clearly state any assumptions made.

Calculate an expression for the electric potential energy of 6 equally charged particles distributed on the vertices of a hexagon.

3. In the circuit shown, calculate the current through the resistive load (the 100 Ohms resistor).

What is the voltage difference between the two circles, across the 40 Ohm resistor?

Attachment:- Questions.rar