Imagine you're an engineer making a string of battery powered holiday lights. If a bulb burns out current cannot flow through that bulb any linger (like if the wire at the bulb had been cut). Figure out how to hook up 2 light bulbs and a battery so that when one bulb burns out (or disconnected) the other stays lit.

The 2 light bulbs can be connected in parallel to each other to avoid disconnection when one bulb burns out.

Explanation:

The parallel connection is required not series. A parallel connection is the connection of electronic components (e. g bulbs, LED, resistors, capacitors etc) in such a way that the same voltage is supplied across the ends of the components. While in a series connection, the components are connected to each other end-to-end.

As regard the question, parallel connection ensures that the brightness any of the bulbs is not affected with respect to the other bulbs. And other bulbs continue to function when any burns out. The 2 light bulbs should be connected in parallel to the baterry to avoid disconnection of all the bulbs.