ELECTROTECHNOLOGY 1100
ASSIGNMENT #7

1. A 2000 turn solenoid is energized by a current of 2A. If the reluctance is measured to be 2x106 AT/Wb, calculate the flux in the circuit. (ANS: 2mWb)

2. A, 2500W movement meter is used to construct the following devices. For each device, draw the circuit diagram and calculate:
(a) The resistance to convert it to a 50mA ammeter (ANS: 1W)
(b) The resistance to convert it to a 10V voltmeter (ANS: 497.5kW)
(c) Design a multi-range ammeter to for 1mA, 10m, and 100mA ranges.
(ANS: RSH1 = 0.051W, RSH10 = 0.005W, and RSH100 = 0.0005W)

3. A 30cm conductor is passed at a speed of 55km/hr between 2 poles of a permanent magnet. If the magnet has a flux density of 2mT, calculate the induced voltage in the conductor. (ANS: 9mV)

4. A 2500 turn coil draws a current of 5A and has a flux of 100mWb. Calculate the induced voltage in the coil when the current is:
(a) Switched off in 0.06s (ANS: 4.1V)
(b) Reversed in 500ms (ANS: 1.0V)