HSC Science (General) १२ वीं कक्षा - Maharashtra State Board Important Questions

Distinguish between ‘paramagnetic’ and ‘ferromagnetic’ substances.

The decay constant of radioactive substance is 4.33 x 10^-4 per year. Calculate its half life period.

A circular coil of 300 turns and average area 5 * 10^-3m² carries a current of 15A. Calculate the magnitude of magnetic moment associated with the coil.

Which of the following substances is ductile?

Give any ‘two’ points of differences between diamagnetic and ferromagnetic substances.

In a hydrogen atom, an electron carrying charge 'e' revolves in an orbit of radius 'r' with speed 'v'. Obtain an expression for the magnitude of magnetic moment of a revolving electron.

The magnetic moment of a magnet of dimensions 5 cm × 2.5 cm × 1.25 cm is 3 Am². Calculate the intensity of magnetization.

The susceptibility of magnesium at 200 K is 1.8 x 10^-5. At what temperature will the susceptibility decrease by 6 x 10^-6?

Show that the orbital magnetic dipole moment of a revolving electron is `(eVr)/2`

An electron in an atom revolves around the nucleus in an orbit of radius 0.53 Å. If the frequency of revolution of an electron is 9 x10⁹ MHz, calculate the orbital  angular momentum

[Given : Charge on an electron = 1.6 x 10^–19 C; Gyromagnetic ratio = 8.8 x 10¹⁰ C/kg; π = 3.142]

Find the magnetization of a bar magnet of length 10 cm and cross-sectional area 4 cm², if the magnetic moment is 2 Am².

A meter gauge train is heading north with speed 54 km/hr in earth's magnetic field 3 x 10^-4T. The e.m.f. induced across the axle joining the wheels is ..........

(a) 0.45 mV

(b) 4.5 mV

(c) 45 mV

(d) 450 m V

Draw the diagrams showing the dipole moments in paramagnetic substance when external magnetic field is (a) absent (b) strong

Represent Radioactive Decay curve using relation `N = N_o e^(-lambdat)` graphically

The magnetic susceptibility of annealed iron at saturation is 4224. Find the permeability of
annealed iron at saturation. (μ₀ = 4Π × 10⁻⁷ SI unit)

The electron in the hydrogen atom is moving with a speed of 2.3x10⁶ m/s in an orbit of radius 0.53 Å. Calculate the period of revolution of the electron. (Π = 3.142)

The susceptibility of magnesium at 300 K is 1.2 x 10 ^-5 . What will be its susceptibility at 200 K.

What happens to a ferromagnetic material when its temperature increases above curie temperature?

Answer in brief.

Discuss the Curie law for paramagnetic material.

Determine the series limit of Balmer, Paschen, and Pfund series, given the limit for Lyman series is 912 Å.