Debt mutual funds

I heard that, interest rates and prices of the debt instruments have an inverse relationship. This means they move in opposite directions. For example, a falling interest rate is good for debt mutual funds. When interest rates fall, the bond prices go up and it will boost NAVs of the debt mutual fund schemes.

My question is when interest rate falls how and why bond rates goes up? can some one explain this?
Thanks in advance.

Check out the link below. It’s explained there.

Here is the Link to know everything about the Bonds, Yield, Interest rate etc. Just go through the relevant PPT.