Answer
$9.1\times 10^{-7}\;s$.
Work Step by Step
Frequency $f=1.1\;MHz$
$f=1.1\times 10^6\; Hz$
The relation between frequency and the period is
$f=\frac{1}{T}$
Isolate $T$.
$T=\frac{1}{f}$
Plug value of $f$.
$T=\frac{1}{1.1\times 10^6\;Hz}$
We can write $\frac{1}{Hz}=s$
$T=\frac{1}{1.1\times 10^6}s$
Rounded value.
$T=0.91\times 10^6\;s$
$T=9.1\times 10^{-7}\;s$.
