A painful lesson can be learned by holding an ohm meter to the contacts of a flashbulb.
This uses a single cell battery, an earphone (shown as 600 ohm resistor), and flashbulb (shown as light bulb) in series circuit. If you hear click sound in earphone when you connect circuit, the filament in flashbulb is making connection. If no click when circuit is connected the filament is broken and the flashbulb is defective.
