If silver falls by 0.2 to 5 USD/oz, your margin will lose 0.2*5000= 1000 USD, leaving 3000 USD.

The contract value is 5 * 5000 = 2500 USD. If the silver falls below $5, your deposit will also lose less than $3,000. At this time, the futures company will urge you to make up the deposit.

If you don't make up the margin on time, you will face forced liquidation (closing the position until the margin is enough)