Copper (cu) has crystal structure Atomic mass of Cu is 63.55 gmol^-1 and radius of a copper atom is 0.128 nm, mean speed of conduction electrons in Cu is 1.5 ×10^6 ms^-1 and frequency of vibration of the Cu atoms at 27 °C is 4×10^12 S^-1 Nordheim’s Coefficient of Au in Cu is 5500 Ω −m Caculate (a) the atomic density of copper (b) Estimate the drift mobility of electronics in cu (c) find the resistivity of pure copper cu (d) find the resistivity of copper if 1 at % of Au is mixed in Cu

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

Which of the following components of a pid controlled accumulates the error over time and responds to system error after the error has been accumulated? a)- proportional b)- derivative c)- integral d)- on/off.