New induction CB tripping
Given it's a hob, I'll guess UK or related, 240VAC countries. Doesn't really matter much, the answer holds for wherever you are.

Basically, a gas "hob" or cooktop or stove or range does not use much electrical power. So it will tend to have a small breaker and small, low capacity wiring. The heat comes from burning gas, not electricity.

Changing a gas hob to an electrical induction hob will require a complete refit from the breaker panel to the hob in order to have properly sized wire and breaker for the vastly larger electrical load, as you are now trying to make heat with electricity.