Question 1

A professor in one of the popular universities in Nigeria lives in a four bed room apartment with his family in Abeokuta. Last week he fought openly  in front of IBEDC office for giving him 'outrageous bills' each time the IBEDC officials come to his house. A survey was conducted in his apartment and the following information was made available . Television (1, in use for 8 hours daily, power  rating 200 Watts), Phone chargers(4, in use for 2 hours daily, power rating 5.2 Watts each), Fluorescence fittings (2, in use for 8 hours daily, power 90 Watts), Electric kettle (1, in use for 2 hours daily, power rating 1000 Watts ), Computers (2, in use for 8 hours, power rating 90 Watts), Air_conditioner(1, in use for 8 hours, power rating 1490Watts), Bulbs(5, in use 8 hours, power rating 60 Watts), Ceiling fan(4, in use 8 hours, power rating 85 Watts), Radio(1, in use 8 hours, power rating 26 Watts), Printers(1, in use for 3 hours, power rating 1200 Watts), Stabilizer(1, in use for 8 hours, power rating 2000 Watts), UPS (1, in use for 8 hours, power rating 1000 Watts), Photocopier (1, in use for 3 hours, power rating 3500 Watts), Refrigerator (1, in use for 6 hours, power rating 200 watts), Others(1, in use for 5 hours, power rating 60 Watts).

   (a)   use the information above to prepare a table with the following headings: Equipment, Quantity, Hours of operations, Power rating and Energy consumed in the professor's house.

(b) estimate the total energy consumed by the professor in a month and per annum.

(c) if IBEDC tariff is N15/kWh, what is the average bill per month and per annum... 

Question 2

(a) State four examples of irreversible process in thermodynamics 

(b) A U-tube mercury thermometer with one arm opened to the atmosphere  is used to measure pressure in a steam pipe. The level of mercury in the open arm is 975mm greater than that in the  arm connecting to the pipe. Some of steam on the pipe condenses in the manometer arm connected to the pipe. The height of of this arm is 34 mm. The atmospheric pressure is 760mm of Hg. Find the absolute pressure of steam.

(c) with diagram only, describe (i) positive work and (ii) negative work..

(d)define the term internal reversibility and state one example.

Question 3

(a) State the equation that relates absolute pressure, atmospheric pressure and gauge pressure.

(b) state and briefly describe  two pressure measuring instruments.

(c) Convert the following readings of pressure to kpa, assuming that barometric reading is 760mm of Hg.

(i) pressure of 80cm of Hg

(ii) 30  cm Hg vacuum and

(iii) pressure due to 1.35m H₂ O gauge

(d) define the term reversible process and state two examples of nearly reversible processes

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