A conducting rod is moved at right angles to a uniform magnetic field. A voltage sensor connected across the rod records a positive reading. The rod can be moved in either direction, and the magnet assembly can be turned around to reverse the magnetic field.
Which change would produce a reading with the same polarity and magnitude as the first reading?
Keep the field and direction unchanged, but move the rod at a higher speed.
Reverse the rod's motion only, keeping its speed unchanged.
Turn the magnet assembly around only, keeping the rod's motion unchanged.
Turn the magnet assembly around and reverse the rod's motion, keeping the speed unchanged.
92 exam-style questions on Edexcel GCSE Physics 13.1 Inducing a current, covering 13.1.1 Producing an electric current by induction, 13.1.2 Factors affecting the induced potential difference, 13.1.3 Alternators and dynamos, and 13.1.4 Microphones and loudspeakers. Each one has a worked solution and a mark scheme showing where the marks go.