HSC Science (Computer Science) 12th Standard Board Exam - Maharashtra State Board Important Questions for Physics

Derive the relation between magnetic field intensity(H) and magnetization(M) for a magnetic material placed in a magnetic field. 

In Hydrogen, the electron jumps from the fourth orbit to the second orbit. The wavenumber of the radiations emitted by an electron is ______  

Show that half life period of radioactive material varies inversely to decay constant λ.

The half-life of a certain radioactive nucleus is 3.2 days. Calculate (i) decay constant (ii) average life of radioactive nucleus.

Show that for radioactive decay N(t) = `"N"_"O" "e"^{-λ"t"}`, where symbols have their usual meaning.

Obtain an expression for the half-lifetime of radioactive material. Hence state the relation between an average life and half life time of radioactive material.

A radioactive substance decays to (1/10)^th of its original value in 56 days. Calculate its decay constant. 

Determine the shortest wavelengths of Balmer and Pasch en series. Given the limit for the Lyman series is 912 Å.

The disintegration rate of a radio-active sample is 10¹⁰ per hour at 20 hours from the start. It reduces to 5 × 10⁹ per hour after 30 hours. Calculate the decay constant.

State unit and dimensions of Magnetic susceptibility.

What is binding energy of a hydrogen atom?

Calculate the wavelength of the first two lines in the Balmer series of hydrogen atoms.

The co-efficient of mutual induction between primary and secondary coil is 2H. Calculate induced e.m.f. if current of 4A is cut off in 2.5 x 10^-4 seconds

Electric field intensity in free space at a distance ‘r’ outside the charged conducting sphere of radius ‘R’ in terms of surface charge density ‘ a ’ is............................

(a)`sigma / in_0[R/r]^2`

(b)`in_0/sigma[R/r]^2`

(c)`R/r[sigma/in_0]^2`

(d)`R/sigma[r/in_0]^2`

A solenoid 3.142m long and 5.0 cm in diameter has two layers of windings of 500 turns each and carries a current of 5A. Calculate the magnetic induction at its centre along the axis.

The magnetic flux through a loop varies according to the relation Φ = 8t² + 6t + C, where ‘C’ is constant, 'Φ' is in milliweber and 't' is in second. What is the magnitude of induced e.m.f. in the loop at t = 2 seconds.

Two metal spheres having charge densities 5μC/m² and -2μC/m² with radii 2mm and  1mm respectively are kept in a hypothetical closed surface. Calculate total normal electric induction over the closed surface.

Obtain an expression for e.m.f. induced in a coil rotating with uniform angular velocity in a uniform magnetic field. Show graphically the variation of e.m.f. with time (t).

Resistance of a potentiometer wire is 0.1Ω/cm. A cell of e.m.f 1.5V is balanced at 300 cm on this potentiometer wire. Calculate the current and balancing length for another cell of e.m.f. 1.4V on the same potentiometer wire.

Discuss the composition of two S.H.M.s along the same path having same period. Find the resultant amplitude and intial phase.

Obtain an expression for average power dissipated in a purely resistive A.C. circult.