What is the correct value of the wavelength of the fourth spectral line (£51) in the Lyman series of the hydrogen spectrum?

If 0.8m is the distance between the two insulated charged spheres of charges 8.5 x10‘7 C each, then what is the force when the charges are doubled and the distance of separation among them is halved?

In a Young's experiment, 3 mm is the width of the fringes obtained with light having a wavelength of 9000 A. If the entire apparatus is immersed in a liquid of refractive index 1.33, then what is the fringe width?

The radius of the nucleus is smaller than the radius of an atom by which of the following factors?

Calculate the mass defect of Oxygen (atomic mass = 16, atomic number = 8) in MeV/cz.

In relation to spectral series, which of the following options correctly states the Brackett series? (Consider that A is the wavelength, R is Rydberg constant, and n may have integral values.)

Restless tectonic plates move (shift) between one and fifteen centimeters per __________.

Stern observed all of the following results except _______ in his experiment.

A compass in a magnetic field will line up __________.

_____ is the property of increasing pitch that accompanies increases in the tones frequency.

As __________________ decreases, then light energy increases.