Which equilibrium can be described as an acid-base reaction using the Lewis acid-base definition but not using the Bronsted-Lowry definition?

The diameters of a circle are along $2x+y-7=0$ and $x+3y-11=0$. Then,the equation of this circle,which also passes through $(5,7)$,is

The electron affinity of sulfur is ...........

Consider the following statements regarding the major pigments and stored food in the different groups of algae and select the correct option.
$I.$ In Chlorophyceae, the stored food material is starch and the major pigments are chlorophyll-$a$ and chlorophyll-$b$.
$II.$ In Phaeophyceae, laminarin is the stored food and major pigments are chlorophyll-$a$ and chlorophyll-$c$.
$III.$ In Rhodophyceae, floridean starch is the stored food and major pigments are chlorophyll-$a$, $d$ and phycoerythrin.

Which one of the following elements,when present as an impurity in silicon,makes it a $p$-type semiconductor?

$A$ tension of $20 ~N$ is applied to a copper wire of cross-sectional area $0.01 ~cm^2$. The Young's modulus of copper is $1.1 \times 10^{11} ~N/m^2$ and the Poisson's ratio is $0.32$. The decrease in the cross-sectional area of the wire is: