\(2I\)
\(6I\)
\(5I\)
\(7I\)
\(IP = I+9I+2\sqrt {I\times9I} \ cos \frac {\pi}{2}= 10I\)
\(IP = I+9I+2\sqrt {I\times9I} \ cos \pi= 14I\)
Then, the difference between the resultant intensities
\(I_P - I_Q = 6I\)
Hence, the correct option is (B): \(6I\)
Let \( \alpha = \dfrac{-1 + i\sqrt{3}}{2} \) and \( \beta = \dfrac{-1 - i\sqrt{3}}{2} \), where \( i = \sqrt{-1} \). If
\[ (7 - 7\alpha + 9\beta)^{20} + (9 + 7\alpha - 7\beta)^{20} + (-7 + 9\alpha + 7\beta)^{20} + (14 + 7\alpha + 7\beta)^{20} = m^{10}, \] then the value of \( m \) is ___________.