It is required to pump cooling water from a storage pond to a condenser in a process plant situated 10m above the level of the pond. 200m of 74.2 mmid pipe
is available and the pump has the characteristics given below. The head loss in
the condenser is equivalent to 16 velocity heads based on the flow in the 74.2mm
pipe. If the friction factor is 0.003, estimate the rate of flow and power to be
supplied to the pump assuming 50% efficiency.
(10 marks
Discharge[m3/s)
10.8
14.04
18.0
20.16
2124
Head developed (mm) 0.0232
0.0213
0.0189
0.0152
0.011
​

The heater element of a 120 v toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. the resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 ω·m. the toaster is operated at a voltage of 120 v. (a) what is the power drawn by the toaster? (b) if the cost of electricity is 12 ¢ per kilowatt-hour, and it takes 2 minutes to toast bread, how much does it cost for toasted bread? (c) when the heater element is at room temperature, is the resistivity in the nichrome wire greater than, less than, or equal to it’s resistivity when at operating temperature? explain.