The intensity of the light from a bulb incident on a surface is $0.22 \mathrm {~W} \mathrm {~m} ^ { - 2 }$. The amplitude of the magnetic field in this light-wave is $\_\_\_\_$ $\times 10 ^ { - 9 } \mathrm {~T}$\\
(Given : Permittivity of vacuum $\epsilon _ { 0 } = 8.85 \times 10 ^ { - 12 } \mathrm { C } ^ { 2 } \mathrm {~N} ^ { - 1 } \mathrm {~m} ^ { - 2 }$, speed of light in vacuum $c = 3 \times 10 ^ { 8 } \mathrm {~m} \mathrm {~s} ^ { - 1 }$ )