Two discs of moment of inertia ' $\mathrm{I}_1$ ' and ' $\mathrm{I}_2$ ' and angular speeds ' $\omega_1$ ' and ' $\omega_2$ ' are rotating along the collinear axes passing through their centre of mass and perpendicular to their plane. If the two discs are made to rotate together along the same axis. The rotational kinetic energy of the system will be

A wire has a mass $0.3 \pm 0.003$ gram, radius $0.5 \pm 0.005 \mathrm{~mm}$ and length $6 \pm 0.06 \mathrm{~cm}$. The maximum percentage error in the measurement of its density is

Two particles ' $A$ ' and ' $B$ ' execute SHMs of periods ' $T$ ' and $\frac{3 T}{2}$. If they start from the mean position then the phase difference between them, when the particle ' $A$ ' completes two oscillations will be

The current (I) drawn from the battery in the given circuit is