If the federal open market committee decides to increase the money supply, then

the Federal Reserve creates dollars and uses them to purchase government bonds from the public.

Explanation:

The money supply is increased by the Federal Reserve Open Market Committee under expansionary monetary policy actions to increase the level of aggregate demand in the market and push the level of output when business activity in the economy is low and the economy is experiencing a recession.

The FOMC creates dollars and uses them to purchase government bonds from the public that injects money in the market by increasing the credit creation capacity of commercial banks. As the money supply increases, the spending capacity of consumers is increased, either by lowering the cost of debt on their credit cards or by increasing employment in the market with increased investments by firms as they borrow with greater zeal when the cost of borrowing is low.