Final answer:
The energy dissipated in the series motor can be calculated by subtracting the kinetic energy gained by the motor and load from the total energy consumed from the electrical supply during the motor's acceleration to 1910rpm.
Step-by-step explanation:
The student is asking about the energy dissipated in a series motor that starts from rest and accelerates to a steady state speed of 1910rpm while connected to a 230 V supply, drawing a current of 20 A. The resistance of the armature and field is given as 1.5Ω, and the moment of inertia of the motor and load is 5 kg-m². To find the energy dissipated during the startup, we first need to identify the energy consumed from the electrical supply and then subtract the kinetic energy gained by the motor and load as they reach the target speed.
Energy consumed (Etotal) can be found using the formula: Etotal = V * I * t, where V is the supply voltage, I is the current, and t is the time to reach the steady state speed. The kinetic energy (Ekinetic) of the motor-load system is given by the formula: Ekinetic = 0.5 * Imoment * ω2, where Imoment is the moment of inertia and ω is the angular velocity in radians per second.
First, we convert 1910 rpm to rad/s: ω = 1910 * 2π / 60. We then calculate Ekinetic: Ekinetic = 0.5 * 5 * (ω2). Next, we calculate Etotal: Etotal = 230 * 20 * 2.5. Lastly, to find the energy dissipated (Edissipated) as heat in the resistance, we subtract Ekinetic from Etotal.
The student should be able to carry out these calculations to find the energy dissipated in the motor during startup. The question primarily deals with concepts of electromechanical energy conversion, electric circuits, power, and kinetic energy. It requires knowledge of physics and electrical engineering.