Induced EMF and Coil Orientation in AC Generator Steps:

• Induced EMF is maximum when coil plane is parallel to magnetic field (flux zero), at 0° or 180° depending on rotation direction.
• Induced EMF is zero when coil plane is perpendicular to magnetic field (flux maximum), at 90°.
• Oscilloscope trace is sinusoidal EMF vs. time; points 1, 2, 3 correspond to zero (point 1), negative peak (point 2), positive peak (point 3).
• Thus, angles are 90° (perpendicular, zero EMF), 180° (parallel, negative max EMF), 0° (parallel, positive max EMF).

Why C is correct:

• Matches Faraday's law: EMF = -dΦ/dt, zero at dΦ/dt=0 (Φ max, plane at 90°), max at Φ=0 (plane parallel at 0°/180°).

Why the others are wrong:

• A: Starts with 0° (max EMF) but point 1 is zero EMF on trace.
• B: Identical to A, incorrect for same reason.
• D: 270° implies another zero position, but point 2 is peak, not zero.

Final answer: C