AREA 3 (AB STRUCTURES & ENVIRONMENT ENGINEERING & BIOPROCESS ENGINEERING & ALLIED SUBJECTS) - VOLUME 7

PROBLEM 1: What is the peak solar power generation per charging channel of a solar battery charging station equipped with 12 units of 75 watt-peak 12-volt solar module? The system is divided into 3 charging channels, each channel has 4 modules connected in parallel. Assume 80% overall efficiency

PROBLEM 2: The initial volume of a certain gas is 528 cc at 45 kPa pressure. During an isothermal process, the volume of gas increased to 888 cc. What is the pressure of the gas after the process?

PROBLEM 3: Determine the size of the digester required to produce biogas for a livestock farm having 500 heads of cattle. The projected retention time is 25 days with 1:1.5 feed material-to-water ratio.

PROBLEM 4: A transformer rated at a maximum of 25 kVA supplies 12-kW at a power factor of 0.60 logging. What percent of the transformer rating does this load represent?

PROBLEM 5: A 10 hp, 3 phase, 60 Hz, and 4-pole squirrel cage induction motor is to be used as a power source of an agricultural processing system. The nameplate of the motor indicated that it efficiency of 90%, power factor of 0.80, and 10% slip at full-voltage. Starting torque is twice the full load torque, and starting current is 85 amp.

• What is the full-load speed (rpm) of this motor?
• If the full load voltage is 230 volts, what is the full-load current (amp)?
• The full load torque (lb-ft) of the motor is ____?

PROBLEM 6: A sinusoidal voltage source with V(eff) = 110V delivers electric power to an impedance of z = 10 + j8 ohms.

• What is the current (amp) delivered?
• What is the power (Watts) delivered?
• What is the power factor?