studyn

"If rate rises than the PV of the bond will be at discount, how come interest rate yields on longer maturities will be high? "

You answered your own question here. As you said, when interest rates rise, the PV (or price) of the bond will be at a deeper discount, so the yield will be higher. Buying a $1000 par-value bond for $600 will have a higher yield than buying it for $800.