Which of the following statements is incorrect?

If $a \sin^2 \theta + b \cos^2 \theta = c$,then $\tan^2 \theta$ is equal to

$A$ finite ladder is constructed by connecting several sections of $2\,\mu F$ and $4\,\mu F$ capacitor combinations as shown in the figure. It is terminated by a capacitor of capacitance $C$. What value should be chosen for $C$ such that the equivalent capacitance of the ladder between the points $A$ and $B$ becomes independent of the number of sections in between? (Answer in $\mu F$)

An electron moving with a speed $u$ along the positive $x-$ axis at $y = 0$ enters a region of uniform magnetic field $\vec{B} = -B_0\hat{k}$ which exists to the right of the $y-$ axis. The electron exits from the region after some time with the speed $v$ at coordinate $y$. Then:

The $IUPAC$ name of $(CH_3)_2CH-CH_2-CH_2Br$ is