Multiple choice

The wire of flash bulb is made of

  1. copper

  2. barium

  3. magnesium

  4. silver

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Flash bulbs used in early photography contained a fine wire or foil made of magnesium or aluminium. When ignited by an electric current, the metal burns rapidly in an oxygen-rich atmosphere, producing a brilliant white flash. Magnesium is the classic material for this purpose.