Ray Optics and Optical Instruments — Physics STD 12 Science — Question

If the self-inductance of an iron core inductor increases from 0·01mH to 10mH on introducing the iron core into it, what is the relative permeability of the core material used?

A drop of mercury of radius 2mm is split into 8 identical droplets. Find the increase in surface energy. Surface tension of mercury = 0.465J/m².

What is the speed of light in a denser medium of polarising angle 30°?

If all the terms in an equation have same units, is it necessary that they have same dimensions? If all the terms in an equation have same dimensions, is it necessary that they have same units?

What will have the effect of moving the plates of a charged capacitor away from each other, on the potential difference between the plates?

Write phase difference between applied emf and current in pure resistor, inductor and capacitor.

A charged particle is projected at a very high speed perpendicular to a uniform magnetic field. The particle will:

1. Move along a circle.
2. Move along a curve with increasing radius of curvature.
3. Move along a curve with decreasing radius of curvature.
4. Move along a straight line.

How electromagnetic radio waves are produced?

When a p-type impurity is doped in a semiconductor, a large number of holes are created. This does not make the semiconductor charged. But when holes diffluse from the p-side to the n-side in a p-n junction, the n-side gets positively charged. Explain.

A small creature moves with constant speed in a vertical circle on a bright day. Does its shadow formed by the sun on a horizontal plane move in a simple harmonic motion?