Energy of an electron in an excited hydrogen atom is -3.4 eV. 1ts angular momentum will be: $h=6.626 \times 10^{-34}$ J-s

$1.11 \times 10^{34}$ J sec $1.51 \times 10^{-31}$ J sec $2.11 \times 10^{-34}$ J sec $3.72 \times 10^{-34}$ J sec

$2.11 \times 10^{-34}$ J sec

The electron is in the second orbit (n = 2). Hence $L=\frac{n h}{2 \pi}=\frac{2 h}{2 \pi}=\frac{6.6 \times 10^{-34}}{\pi}=2.11 \times 10^{-34}$ J - sec