Question

1. When the current in a toroidal solenoid is changing at a rate of 0.0270 A/s , the magnitude of the induced emf is 12.6 mV . When the current equals 1.40 A , the average flux through each turn of the solenoid is 0.00320 Wb .How many turns does the solenoid have?

2. You need a transformer that will draw 33 W of power from a 220 V (rms) power line, stepping the voltage down to 12 V (rms). a. What will be the current in the secondary coil? b. What should be the resistance of the secondary circuit? What will be the equivalent resistance of the input circuit?

3. An air-filled toroidal solenoid has a mean radius of 17.0 cm and a cross-sectional area of 7.00 cm2 . When the current is 11.5 A , the energy stored is 0.350 J .How many turns does the winding have?

4. a. What would have to be the self-inductance of a solenoid for it to store 10.0 J of energy when a 1.50 A current runs through it? b. If this solenoid's cross-sectional diameter is 3.80 cm , and if you could wrap its coils to a density of 10 coils/mm , how long would the solenoid be?

5. A 12.0 V dc battery having no appreciable internal resistance, a 153.0 Ω resistor, an 11.4 mH inductor, and an open switch are all connected in series. a. After the switch is closed, what is the time constant for this circuit ? b. After the switch is closed, what is the maximum current that flows through it ? c. What is the current 74.3 μs after the switch is closed ? d. After the switch is closed, what is the maximum energy stored in the inductor?

Answer 1