If $f: R \rightarrow R$ is defined by $f(x) = 7 + \cos(5x + 3)$ for $x \in R$,then the period of $f$ is

Which of the following oxides will produce hydrogen peroxide upon reaction with dilute acid?

Two vibrating tuning forks produce progressive waves given by $Y_1 = 4 \sin(500 \pi t)$ and $Y_2 = 2 \sin(506 \pi t)$. The number of beats produced per minute is:

If $\frac{x^2}{a} + \frac{2xy}{h} + \frac{y^2}{b} = 0$ represents a pair of straight lines such that the slope of one of the lines is twice the other,then $\frac{ab}{h^2} =$

$A$ magnetic needle is kept in a non-uniform magnetic field. It experiences

$S$ and $T$ are the foci of an ellipse and $B$ is an end point of the minor axis. If $\triangle STB$ is an equilateral triangle, then the eccentricity of the ellipse is: