Physics

Alternating Current is the type of current whose direction isn't uniform and can change constantly. On the other hand, dc current is the type of current who can have a single direction only. DC is a comparatively low quality current as compared to an AC current.

Inside a spherical shell gravitational field is zero, so net force acting on a particle placed inside it is also zero.

Total energy of a bound system is always negative.

According to this chapter, a galvanometer is used to find and measure the small electric currents in a circuit. The principle that works in a galvanometer is the electromagnetic induction.

There are two types of electricity - Static and Current electricity. The electric charges buildup on a material's surface is called the static electricity. The continuous flow of electric charge is termed as the current electricity. Current electricity is of two types - Alternating Current (AC) and Direct Current (DC). In AC, the charge direction reverses periodically and in DC, charge flows in one direction.

According to Einstein's photoelectric equation maximum kinetic energy of photoelectrons, $K{E}_{ max }=E_v-\phi$

or   $2=5-\phi$ $\therefore \phi =3eV$

When $E_v=6eV$  then, $K{E}_{ max }=6-3=3eV$

or $e\left(V_{cathode}-V_{anode}\right)=3eV$

or   $V_{cathode}-V_{anode}=3V=-V_{stopping}$

  $\therefore V_{stopping}=-3V$

Elastic potential energy stored in the spring

$U=\frac{1}{2}k{x}^2$

$=\frac{1}{2}Fx=\frac{F^2}{2k}$

$Hence\frac{U_1}{U_2}=\frac{k_2}{k_1}\left. [Fissameforbothsprings\right]$

$=\frac{500}{1200}=\frac{5}{12}$

The current's SI unit is ampere. The symbol for ampere is A. The term ampere is named after the French physicist André-Marie Ampère.

In simple words, current electricity can be defined as the electric charge continuously moving from one place to another along a pathway. It is measured in amperes (A). Electric current is needed for electrical devices to work.