An electromagnet's current is falling. Is an EMF induced in a loop resting beside it?
Quinn winds a coil of 20 turns and pushes a magnet in at a steady speed. A meter across the coil reads the induced EMF, and the reading peaks at 0.2 V. Then he rewinds the same wire into a coil of 40 turns.
Same magnet, same speed. Only the number of turns changes.
Quinn pushes the magnet into the 40-turn coil at the same steady speed. The reading now peaks at 0.4 V. The coil with more turns gives a bigger EMF.
Why? The changing field passes through every turn of the coil. Each turn adds to the coil's EMF.
So a coil with more turns gives a bigger EMF for the same change.
The coil is rewound with more turns; same magnet, same speed. What happens to the EMF?
The coil is rewound with fewer turns; same magnet, same speed. What happens to the EMF?
Asha rewinds a 30-turn coil into a 60-turn coil and pushes the same magnet in at the same speed. What happens to the EMF?
The magnet and the speed are unchanged; only the turn count changed.
The changing field passes through every turn, and each turn adds to the EMF.
Sixty turns add more than thirty turns.
The EMF gets bigger.
A coil is rewound with fewer turns, and the same magnet enters it at the same speed. What happens to the EMF?
The magnet and the speed are unchanged; only the turn count changed.
Each turn adds to the EMF, and now there are fewer turns adding.
The EMF gets smaller.
Two coils: 10 turns and 50 turns. The same magnet enters each at the same speed. Which gives the larger EMF?
Asha winds three coils: 15 turns, 35 turns, and 60 turns. The same magnet enters each at the same speed. Which coil gives the smallest EMF?
Which observation shows that more turns give a bigger EMF?
A 60-turn coil gives a bigger EMF than a 20-turn coil for the same magnet at the same speed. Why?