Define electromotive force. A cell of e. m.f. E and internal resistancer was connected in series with two series
external resistors, A (of 8-ohms) and B (of 2-ohms). A high resistance voltmeter
connected across A was found to read Svolts. When another resistor C (of 8 ohms)
was connected parallel to A, and then across A and C. the voltmeter read 6 volts.
Draw the circuit diagrams of the two arrangements.

Calculate the internal resistance of the cell.
Calculate the e. m.f. of the cell.
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4r-134a enters the condenser of a residential heat pump at 800 kpa and 50°c at a rate of 0.022 kg/s and leaves at 750 kpa subcooled by 3°c. the refrigerant enters the compressor at 200 kpa superheated by 4°c determine (a) the isentropic efficiency of the compressor, (b) the rate of heat supplied to the heated room, and (c) the cop of the heat pump. also, determine (d) the cop and rate of heat supplied to the heated room if this heat pump operated on the ideal vapor-compression cycle between the pressure limits of 200 and 800 kpa. (0.757, 4.37 kw, 5.12, 6.18, 3.91 kw)

In a system with only a single force acting upon a body, what is the relationship between the change in kinetic energy and the work done by the force? answers: work is equal to the change in kinetic energy.work depends on the square of the change in potential energy.work is equal to the negative of the change in kinetic energy.work is equal to the square of the change in kinetic energy

Why do atoms emit energy of only specific wavelengths