The following compound is used as:

The coefficient of thermal conductivity of copper is nine times that of steel. In the composite cylindrical bar shown in the figure,what will be the temperature at the junction of copper and steel in $^oC$?

$A$ variable circle passes through the fixed point $A(p, q)$ and touches the $x$-axis. The locus of the other end of the diameter through $A$ is

The centroid of the triangle formed by the lines $6x^2 + xy - y^2 = 0$ and $x + 3y - 10 = 0$ is

Which of the following bonds is the most polar?

An infinitely long straight conductor $AB$ is fixed and a current $i_1$ is passed through it. Another movable straight wire $CD$ of finite length carrying current $i_2$ is held perpendicular to it and released. Neglect the weight of the wire.