The spectrum of a black body at two temperatures $27^oC$ and $327^oC$ is shown in the figure. Let $A_1$ and $A_2$ be the areas under the two curves respectively. The value of $\frac{A_2}{A_1}$ is

When a liquid is heated in a copper vessel, its coefficient of apparent expansion is $6 \times 10^{-6} /{ }^{\circ} C$. When the same liquid is heated in a steel vessel, its coefficient of apparent expansion is $24 \times 10^{-6} /{ }^{\circ} C$. If the coefficient of linear expansion for copper is $18 \times 10^{-6} /{ }^{\circ} C$, what is the coefficient of linear expansion for steel?

Which one of the following statements is correct about biodiversity?

In a metre bridge experiment,the ratio of the left gap resistance to the right gap resistance is $2:3$. The balance point from the left is: (in $~cm$)

Statement $1$: If the points $(1,2,2), (2,1,2), (2,2,z)$ and $(1,1,1)$ are coplanar,then $z=2$.
Statement $2$: If the $4$ points $P, Q, R$ and $S$ are coplanar,then the volume of the tetrahedron $PQRS$ is $0$.

If the slope of one line is twice the slope of the other in the pair of straight lines $ax^2 + 2hxy + by^2 = 0$,then $8h^2$ is equal to (in $ab$)