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

The magnetic flux through a loop varies according to the relation Φ = 8t² + 6t + 2, Φ is in milliweber and t is in second. What is the magnitude of the induced emf in the loop at t = 2 seconds?  

Explain step up and step down transformer?

Determine the motional emf induced in a straight conductor moving in a uniform magnetic field with constant velocity on the basis of Lorentz force.

The primary of a transformer has 40 turns and works on 100 V and 100 W. Find a number of turns in the secondary to step up the voltage to 400 V. Also calculate the current in the secondary and primary.

Using Ampere's law, obtain an expression for the magnetic induction near a current-carrying straight infinitely long wire. 

Describe the construction and working of a transformer with a neat labelled diagram.

In a series LCR circuit, the phase difference between the voltage and the current is 45°. Then the power factor will be ______.

State any two characteristics of a series LCR AC resonance circuit.

Find the current in a circuit consisting of a coil and a capacitor in series with an A.C source of 110V (r.m.s.), 60Hz. The inductance of a coil is 0.80 H and its resistance is 50Ω. The capacitance of a capacitor is 8µF. 

A radio can tune over the frequency range of a portion of the MW broadcast band (800kHz -1200kHz). If its LC circuit has an effective inductance of 200mH, what must be the range of its variable condenser? 

If the frequency of incident light falling on a photosensitive material is doubled, then the kinetic energy of the emitted photoelectron will be ______.

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

(A) Electrons

(B) Protons

(C) Deuterons

(D) α- particles

State Ampere’s circuital law.

Obtain an expression for magnetic induction along the axis of the toroid.

State the importance of Davisson and Germer experiment.

Draw a neat labelled diagram of a schematic of the experimental setup for the photoelectric effect. 

With the help of a circuit diagram describing an experiment to study the photoelectric effect.

The energy of a photon is 2 eV. Find its frequency and wavelength.  

The work function of a surface is 3.1 eV. A photon of frequency 1 × 10¹⁵ Hz. Is an incident on it. Calculate the incident wavelength is photoelectric emission occurs or not.   

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]