Question Bank [ 2022 ] — Physics STD 12 Science — Question

Explain the working of a transformer with a neat, labelled diagram.

Obtain the expression for current sensitivity of moving coil galvanometer.

A voltmeter has a resistance of \(100 \Omega\). What will be its reading when it is connected across a cell of e.m.f. \(2 V\) and internal resistance \(20 \Omega\) ?

Draw a neat labelled diagram for a liquid surface in contact with a solid, when the angle of contact is acute.

A body cools at the rate of \(0.5^{\circ} C / min\), when it is \(25^{\circ} C\) above the surroundings. Calculate the rate of cooling when it is \(15^{\circ} C\) above the same surroundings.

A uniform solid sphere has a radius \(0.1 m\) and density \(6 \times 10^3 kg / m ^3\). Find its moment of inertia about a tangent to its surface.

Derive the relation between surface tension and surface energy per unit area.

Calculate the value of magnetic field at a distance of \(3 cm\) from a very long straight wire carrying a current of \(6 A\).

Define U.C.M. Name the forces acting on a body executing non-uniform circular motion.