The value of $\sqrt{(\log_{0.5} 4)^2}$ is

An object is attached to the bottom of a light vertical spring and set vibrating. The maximum speed of the object is $15 ~cm/s$ and the period is $628 ~ms$. The amplitude of the motion in $cm$ is:

In a meter bridge experiment,a null point is obtained at $l \text{ cm}$ from the left end. If the meter bridge wire is replaced by a wire of the same material but twice the area of cross-section,then the null point is obtained at a distance:

From the point $(-1, 2)$,tangents are drawn to the parabola $y^2 = 4x$. Find the area of the triangle formed by the chord of contact and the tangents. (in $sqrt{2}$)

From the following statements,select the wrong one:

Among $TiF_6^{2-}, CoF_6^{3-}, Cu_2Cl_2$ and $NiCl_4^{2-}$,the colourless species are: