Which of the following ions forms a hydroxide that is readily soluble in water?

If the axes are rotated through an angle $45^{\circ}$ in the positive direction without changing the origin,then the coordinates of the point $(\sqrt{2}, 4)$ in the old system are

To increase milk yield,a cow is given:

The circuit has two oppositely connected ideal diodes in parallel. What is the current flowing in the circuit (in $A$)?

Phosgene is formed slowly from which one of the following on exposure to air and sunlight?

Power delivered by the $ac$ source of the circuit becomes maximum when