The lowering of the Bank Rate by the Reserve Bank of India (RBI) reduces the cost of borrowing for commercial banks, allowing them to lend money at lower interest rates. This increased availability of credit enhances liquidity in the market, stimulating economic activity by encouraging consumer spending and investment. In the context of monetary policy, this mechanism is a tool used by central banks to manage inflation and economic growth, making it a fundamental concept relevant for UPSC Prelims.