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

In the hysteresis cycle, the value of H needed to make the intensity of magnetism zero is called:

The difference in the lengths of a mean solar day and a sidereal day is about(a) 1 min(b) 4 min(c) 15 min(d) 56 min

If ionisation energy of hydrogen atom in ground state is 13.6 eV , then ionisation energy of first excited state will be :

Assertion : Short wave bands are used for transmission of radio waves to a large distance.
Reason    :  Short waves are reflected by ionosphere(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

A magnifying glass is used, as the object to be viewed can be brought closer to the eye than the normal near point. This results in;

The size of an object as perceived by an eye depends primarily on:

When light falls on matter, it can produce:

An element has number of proton = 7. Then what will be its atomic number?

The interfering fringes formed by a thin oil film on water are seen in yellow light of sodium lamp. We find the fringes: