Nuclei — Physics STD 12 Science — Question

The human eye has a lens which has a(a) Soft portion at its centre(b) Hard surface(c) Varying refractive index(d) Constant refractive index

A particle is fastened at the end of a string and is whirled in a vertical circle with the other end of the string being fixed. The motion of the particle is:

1. Periodic.
2. Oscillatory.
3. Simple harmonic.
4. Angular simple harmonic.

To demonstrate the phenomenon of interference, we require two sources which emit radiation(a) Of the same frequency and having a define phase relationship(b) Of nearly the same frequency(c) Of the same frequency (d) Of different wavelengths

Which of the following is vector quantity(a) Current density(b) Current(c) Wattless current(d) Power

Energy conversion in a photoelectric cell takes place from(a) Chemical to electrical(b) Magnetic to electrical(c) Optical to electrical(d) Mechanical to electrical

In Bohr’s model electrons are revolving in a circular orbits around the nucleus called as:

Three charges 2q, -q, -q  are located at the vertices of an equilateral triangle. At the centre of the triangle(a) The field is zero but potential is non-zero(b) The field is non-zero but potential is zero(c) Both field and potential are zero(d) Both field and potential are non-zero

Two photons having _________________:

Core of electromagnets are made of ferromagnetic material which has: