HSC Science (Electronics) 12th Standard Board Exam - Maharashtra State Board Important Questions

Four resistances 6Ω, 6Ω, 6Ω and 18Ω form a Wheatstone bridge. Find the resistance which connected across the 18Ω resistance will balance the network.

Explain with a neat circuit diagram. How you will determine the unknown resistances using a meter bridge.

Which one of the following particles cannot be accelerated by a cyclotron?

(A) Electrons

(B) Protons

(C) Deuterons

(D) α- particles

Currents of equal magnitude pass through two long parallel wires having a separation of 1.35 cm. If the force per unit length on each of the wires is 4.76 x 10^-2 N, what must be I ?

A circular loop of radius 9.7 cm carries a current 2.3 A. Obtain the magnitude of the magnetic field
(a) at the centre of the loop
(b) at a distance of 9.7 cm from the centre of the loop but on the axis.

The magnetic field at a distance of 2.4 cm from a long straight [current-carrying] wire is 16 µT. What is the current through the wire?

Derive the expression for magnetic field produced by a current in a circular arc of wire.

Prove that the frequency of beats is equal to the difference between the frequencies of the two sound notes giving rise to beats.

Describe biprism experiment to calculate the wavelength of a monochormatic light. Draw the necessary ray diagram.

An iron rod of the area of cross-section 0.1m² is subjected to a magnetizing field of 1000 A/m. Calculate the magnetic permeability of the iron rod. [Magnetic susceptibility of iron = 59.9, magnetic permeability of vacuum = 4π x 10^-7 S. I. unit]  

Derive an expression for path difference in Young’s double slit experiment and obtain the conditions for constructive and destructive interference at a point on the screen.

Distinguish between the phenomenon of interference and diffraction of light.

Distinguish between diamagnetic and paramagnetic substances.

An electron in an atom is revolving around the nucleus in a circular orbit of a radius of 5.3 x 10^-11 m, with a speed of 2 x 10⁶ m/s. Find the resultant orbital magnetic moment and angular momentum of the electron. [e = 1.6 x 10^-19 C, m_e= 9.1 x 10^-31 kg]

A magnet of magnetic moment 3Am² weighs 75 g. The density of the material of the magnet is 7500 kg/m³. what is magnetization? 

What is magnetic susceptibility?

State SI unit of Magnetization.

Derive an expression for ratio of e.m.f.s and currents in terms of number of turns in primary and secondary coil.

Explain why the inductance of two coils connected in parallel is less than the inductance of either coil.

Why and where are eddy currents are undesirable? How are they minimized?