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

In a photon-electron collision ______.
(A) only total energy is conserved.
(B) only total momentum is conserved.
(C) both total energy and total momentum are conserved.
(D) both total momentum and total energy are not conserved

Find the frequency of revolution of an electron in Bohr’s 2nd orbit; if the radius and speed of electron in that orbit is 2.14 × 10^-10 m and 1.09 × 10⁶ m/s respectively. [π= 3.142]

Draw a neat, labelled energy level diagram for H atom showing the transitions. Explain the series of spectral lines for H atom, whose fixed inner orbit numbers are 3 and 4 respectively.

Thorium ₉₀Th²³² is disintegrated into lead ₈₂Pb²⁰⁰. Find the number of α and β particles emitted in disintegration.

Find the ratio of longest wavelength in Paschen series to shortest wavelength in Balmer series.

The ratio of kinetic energy of an electron in Bohr’s orbit to its total energy in the same orbit  is

(A) – 1

(B) 2

(C) 1/2

(D) – 0.5

In hydrogen atom Balmer series is obtained when the electron jumps from ............ .

(a) higher orbit to first orbit

(b) first orbit to a higher orbit

(c) higher orbit to the second orbit

(d) second orbit to a higher orbit

What is de Broglie wavelength of an electron accelerated through 25000 volt?

Light of wavelength 3000Å falls on a metal surface having work function 2.3 eV. Calculate the maximum velocity of ejected electrons

(Planck's constant h = 6.63 x 10^-34 J.s., Velocity of light c = 3 x 10⁸ m/s, mass of an electron = 9.1 x 10^-31 kg)

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

Write notes on Nuclear fission

Write notes on Nuclear fusion

What do you mean by polar molecules and non-polar molecules? Give ‘one’ example each.

Calculate the de-Broglie wavelength of an electron moving with one-fifth of the speed of light.Neglect relativistic effects. (`h = 6.63 xx 10^(-34)` J.s, c= `3xx10^8`m/s, mass of electron = `9 xx 10^(-31) kg)`

An electron of energy 150 eV has wavelength of 10^-10m. The wavelength of a 0.60 keV electron is?

Using an expression for energy of electron, obtain the Bohr’s formula for hydrogen spectral lines.

What is binding energy of a hydrogen atom?

Which logic gate corresponds to the truth table given below?

Explain the elementary idea of an oscillator with the help of block diagram

In a semiconductor, acceptor impurity is.................................

1. antimony
2. indium
3. phosphorous
4. arsenic