A10mm cube of germanium passes a current of 6.4ma when 10mv is applied between two of its parallel faces. assuming that the charge carriers are electrons that have a mobility of 0.39m^2 v^–1 s^–1 , calculate the density of carriers. what is their collision time if the electron’s effective mass ingermanium is 0.12 m_0 where m_0 is the free electron mass?

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.