Physics

Why couldn't Rutherford explain the stability of an atom?

A circular disc of mass M and radius R is rotating about its axis with angular speed ω₁. If another stationary disc having radius R/2 and same mass M is dropped co-axially on to the rotating disc. Gradually both discs attain constant angular speed ω₂. The energy lost in the process is p% of the initial energy. Value of p is
(Rotational)

In the line spectra of hydrogen atom, difference between the largest and the shortest wavelengths of the Lyman series is 304Å. The corresponding difference for the Paschan series in Å is:

ABC is a plane lamina of the shape of an equilateral triangle. D, E are mid points of AB, AC and G is the centroid of the lamina. Moment of inertia of the lamina about an axis passing through G and perpendicular to the plane ABC is I?. If part ADE is removed, the moment of inertia of the remaining part about the same axis is NI?/16 where N is an integer. Value of N is

In a compound microscope, the magnified virtual image is formed at a distance of 25 cm from the eye-piece. The focal length of its objective lens is 1 cm. If the magnification is 100 and the tube length of the microscope is 20 cm, then the focal length of the eyepiece lens (in cm ) is

A closed vessel contains 0.1 mole of a monatomic ideal gas at 200 K. If 0.05 mole of the same gas at 400 K is added to it, the final equilibrium temperature (in K ) of the gas in the vessel will be close to

A battery of 3.0 V is connected to a resistor dissipating 0.5 W of power. If the terminal voltage of the battery is 2.5 V, the power dissipated within the internal resistance is:

Blocks of masses m, 2m and 8m are arranged in a line on a frictionless floor. Another block of mass m, moving with speed v along the same line (see figure) collides with mass m in perfectly inelastic manner. All the subsequent collisions are also perfectly inelastic. By the time the last block of mass 8 m starts moving the total energy loss is p% of the original energy. Value of ' p ' is close to:

Two charged thin infinite plane sheets of uniform surface charge density σ+and σ−, where |σ+| > |σ−|, intersect at right angle. Which of the following best represents the electric field lines for this system.

Starting from the origin at time t = 0, with initial velocity 5ĵ ms⁻¹, a particle moves in the x-y plane with a constant acceleration of (10î + 4ĵ)ms⁻². At time t, its coordinates are (20 m, y₀m). The values of t and y₀ are, respectively: