The link for question 5,6,7, a,b,c,d is: https://phet.colorado.edu/en/simulation/legacy/generatorAnswer all the bold and the underlines ones
Generator - Faraday's Law | Magnetic Field | Induction - PhET Interactive Simulations (colorado.edu) Open the simulation A generator is a rotating magnet, with a coil of wire near the end of the magnet. These are found as "alternators" under the hood of your car, and in large Megawatt power pants. Our intent here is to show how a "hydropower" generator works. Set up: Click on Show Field and the up arrow on Loops to have 3. Magnetism basics: N pole is red, B field lines come out from it and into the S pole. Some are heading directly into the coil. No B field change means no induced current in the coil. 5. The water tap has a handle, with a slider. Pull the slider about half way to the right, for an indicated 50-55 rpm. Is the portion of the B field going into the coil changing? Yes/No. Is the lamp illuminated by a current induced in the coil, in accord with B field changes? Yes/No. Pull the tap slider completely to the right, 100 rpm. The rate of B field change is now: Higher/Lower. Does the lamp indicate more induced current, in accord with increased B field changes? Yes/No. Finally click on the blue meter icon to the right, it replaces the lamp. The induced current is: AC/DC. Transformer. Click on this tab in the upper part of the simulation. A 10 V battery running a small 4 turn solenoid on the left, meaning an unchanging B field. It is an electromagnet. Unchanging B field, so no induced current in the right hand solenoid. 6. The electron flow is indicated. The current direction is Same/Opposite. RHR 1 implies the B field is to the Right/Left. 7. A. Click on the AC Current Source icon on the upper right. The left coil now clearly has AC (ignore the blue AC current supply). Does this induce a (slight) alternating current in the right hand coil? Yes/No. B. This is Faraday induction from an "AC solenoid" into the right solenoid. Increase its turns to 3 using the Loops button (below the light bulb icon). Does increasing the turns in the right solenoid increase the induced current? Should/Will not. C. Much of the left solenoid's B field lands outside the right solenoid, meaning that if this were a transformer it would be highly inefficient. Yet there is a way to get the left solenoid's "strong B field lines" within the right solenoid. Literally grab it, and move it to the right to be inside the larger, right hand solenoid. Is the induced current in the larger (now outer) solenoid dramatically increased? Yes/No. D. Note that there is yet much B field outside the outer solenoid. The ratio of voltages to turns is not affected by inefficiency, and we have No = 4 with N, = 3. Yet the currents are affected. Assume 50% efficiency, and that lo = 50 mA. What is Is? imA. (the lecture derivation, using .5 Pp = Ps, gives Is = .5 1, No/Ns)
