One turn of insulated wire in the form of a planar square frame with side $l = 0.2\,m$ and resistance $R = 1\,\Omega$ is placed in a uniform magnetic field perpendicular to the plane of the frame. The current passing through the turn when the magnetic field starts to decrease at a constant rate of $0.1\,T/s$ is......$mA$.

If $e$ and $e^{\prime}$ are the eccentricities of the ellipse $5x^2 + 9y^2 = 45$ and the hyperbola $5x^2 - 4y^2 = 45$ respectively,then $ee^{\prime}$ is equal to

The tyre of a motor car contains air at $15^{\circ} C$. If the temperature increases to $35^{\circ} C$,the approximate percentage increase in pressure is (ignore the expansion of the tyre).

Sexual reproduction leads to

When substance $A$ reacts with water,it produces a combustible gas $B$ and a solution of substance $C$ in water. When another substance $D$ reacts with solution $C$,it produces the same gas $B$ even when reacting with dilute sulfuric acid at room temperature. $A$ imparts a golden yellow color to the non-luminous flame of a Bunsen burner. What are $A$,$B$,$C$,and $D$ respectively?

The product of the lengths of perpendiculars drawn from any point on the hyperbola $x^2 - 2y^2 - 2 = 0$ to its asymptotes is