You double the acceleration with the same charge. By what factor does radiated power grow?

• 2
• 4
• 8

Which charge radiates?

• One that accelerates
• One sitting still
• One gliding at steady speed

A charge moving at constant velocity radiates.

Why does a radio antenna emit waves?

• Its electrons sit perfectly still
• Its electrons are pushed back and forth, always accelerating
• Its protons do all the moving

How is the radiation arranged around the acceleration?

• Strongest along the line, zero sideways
• Equal in every direction
• Strongest sideways, zero along the line

Electrons and protons move at the same speed through the same magnetic field. Why do the electrons lose far more energy to light?

• Electrons carry far more charge than protons, so each radiates more
• The same force gives the much lighter electron a far bigger acceleration
• Protons are too heavy for magnets to bend at all, so they never radiate light

Ned expects an accelerating charge to radiate most along its line of acceleration and not at all sideways. What is wrong?

• He used the wrong charge sign
• He picked too low a speed
• He reversed the pattern: peak is sideways, zero along

Which of these is a synchrotron radiation source?

• The Crab Nebula glow
• A steady battery current
• A parked bar magnet