Read the following text and answer the following questions on the basis of the same:
Bottle Dynamo: A bottle dynamo is a small generator to generate electricity to power the bicycle light. Is is not a dynamo. Dynamo generates DC but a bottle dynamo generates AC. Newer models are now available with a rectifier. The available DC can power the light and small electronic gadgets. This is also known as sidewall generator since it operates using a roller placed on the sidewall of bicycle tyre. When the bicycle is in motion, the dynamo roller is engaged and electricity is generated as the tyre spins the roller. When engaged, a dynamo requires the bicycle rider to exert more effort to maintain a given speed than would otherwise be necessary when the dynamo is not present or disengaged. Bottle dynamos can be completely disengaged during day time when cycle light is not in use. In wet conditions, the roller on a bottle dynamo can slip against the surface of the tyre, which interrupts the electricity generated. This cause the lights to go out intermittently.

Bottle generator generates electricity:

Options

A. when fuel is poured in the bottle.
B. when cycle is in motion.
C. when it is mounted properly.
D. when wind blows.

Answer

B

Explanation

Bottle generator is also known as sidewall generator since it operates using a roller placed on the sidewall of bicycle tyre. When the bicycle is in motion, the dynamo roller is engaged and electricity is generated as the tyre spins the roller.