Give the situation in which the determinants of budget line change but the budget line does not change.

The determinants of budget line are money income of the consumer, price of good 1 and price of good 2. Now, the budget line would not change if the percentage change in each of them is the same, such that the ratio of money income to price of good 1 and money income to price of good 2 remains the same as before the change.