Dual Nature of Radiation and Matter — Physics STD 12 Science — Question

A biconcave lens made of a transparent material of refractive index 1.25 is immersed in water of refractive index 1.33. Will the lens behave as a converging or a diverging lens? Give reason.

For same value of angle of incidence, the angles of refraction in three media are 15°, 20° and 25° respectively. In which medium, the velocity of light will be minimum?

Two converging lenses of unequal focal lengths can be used to reduce the aperture of a parallel beam of light without losing the energy of the light. This increases the intensity. Describe how the converging lenses should be placed to do this.

Is the dispersion power of crown glass more or less than that of flint glass? Write.

Answer the following question:
An electron travelling west to east enters a chamber having a uniform electrostatic field in north to south direction. Specify the direction in which a uniform magnetic field should be set up to prevent the electron from deflecting from its straight line path.

In Rutherford's experiment, why the mass of nucleus not important?

Consider the situation of the previous problem. If the mirror reflects only 64% of the light energy falling on it, what will be the ratio of the maximum to the minimum intensity in the interference pattern observed on the screen?

Can a charged particle be accelerated by a magnetic field? Can its speed be increased?