Electron | MCQs

Explanation

The relation between alpha (α) and beta (β) is given by:

β = α / (1 - α)

Given α = 1/2:

β = (1/2) / (1 - 1/2)

= (1/2) / (1/2)

= 1

Explanation

e/m = 2E/B²r²

The formula is derived by equating the magnetic Lorentz force to the centripetal force and using the kinetic energy gained from the accelerating voltage E.

This formula correctly relates the charge-to-mass ratio of an electron to the magnetic field B, radius of the circular path r, and accelerating voltage E.

Explanation

Orbital electrons have specific, quantized energy levels depending on their orbit.

They cannot have arbitrary energy values — only fixed amounts allowed by quantum rules.

Explanation

The kinetic energy (KE) of an electron in the nth orbit is given by:

KE = 1/2mv²n

Where m is the mass of the electron and vn is its velocity in the nth orbit.

Explanation

A capacitor is a passive two-terminal electrical component that can store energy in an electric field electrostatically.

Explanation

The component of an electric circuit that opposes the flow of charges in the circuit is called a resistor.

Explanation

The invention and advancement of the vacuum or electron tube marked the beginning of the Electronic Era in the early 20th century.

These tubes were used in early radios, televisions, and computers.

Explanation

The ePay app is used for paying utility bills and taxes.

It is a digital payment platform that allows users to make payments for services like electricity, gas, water, and other government taxes.

Explanation

A switch is used to control the On/Off state of an electrical circuit.

It allowing current to flow or stopping it when needed.

Explanation

ENIAC was designed by John Mauchly and J. Presper Eckert

ENIAC was completed in 1945

It was first put to work for practical purposes on December 10, 1945