$A$ block of weight $W$ is held against a vertical wall by applying a horizontal force $F$. The minimum value of $F$ needed to hold the block is

An infinitely long thin straight wire has a uniform linear charge density of $\frac{1}{3} ~Cm^{-1}$. The magnitude of the electric field intensity at a point $18 ~cm$ away is (given $\varepsilon_0 = 8.85 \times 10^{-12} ~C^2 N^{-1} m^{-2}$):

If $\omega$ is a complex cube root of unity,then $(x+1)(x+\omega)(x-\omega-1)$ is equal to

The area (in square units) of the region enclosed by the two circles $x^2+y^2=1$ and $(x-1)^2+y^2=1$ is

Injury to the adrenal cortex is not likely to affect the secretion of which one of the following?

The equation of the line passing through the point of intersection of the lines $x-3y+2=0$ and $2x+5y-7=0$ and perpendicular to the line $3x+2y+5=0$ is: