## Manometer

A differential manometer is a simple instrument for comparing pressures, usually by the difference in height of two liquid columns. The simplest of such instrument is a U-tube containing some liquid, usually mercury, water or oil. The pressure exerted by a confined gas changes the levels of the mercury in the manometer. The total pressure of a gas or liquid …

## Second Order Differential Equation

Sub-Topics: Basics Of Second Order Differential Equation Coming soon!   Back To Mathematics For An Undergraduate Physics Course

## Basics Of Second Order Differential Equation

A second order differential equation is of the form $a \frac{d^{2}y}{dx^{2}} + b \frac{dy}{dx} + b \frac{dy}{dx} + cy = f(x)$. $f(x)$ is called a source term or forcing function. The differential equation is called a homogeneous equation IF $f(x) = 0$ non-homogeneous IF $f(x)$ is not 0. The steps involved in solving a homogeneous equation and non-homogeneous are quite …

## O Level: Temporary and permanent magnets

Iron as a temporary magnet: Iron can be easily magnetised or demagnetised (soft magnetic material. It can even be magnetized by a weak magnetic field. it is therefore suitable to be used in temporary magnets. When mixed with other metals (e.g. Ni, Cu, Mn, Si), powerful temporary magnets can be made. These temporary magnets are used to make temporary electromagnets. …

## O Level: Magnetic Field And Magnetic Field Lines

Magnetic Field is the region around a magnet where other magnetic material will experience a force. A magnetic field can be graphically represented by magnetic field lines which indicates its strength and direction. Note: Magnetic field is a vector quantity! (It has both magnitude AND direction!) When the field lines are close together at a point, the point is said …

## UY1: Electric Dipole

An electric dipole is a pair of charges with equal magnitude and opposite sign (a positive charge q and a negative charge -q) separated by a distance d. Consider an electric dipole placed in a uniform external electric field $\vec {E}$.   Electric dipole moment: $p = qd$. Torque on the dipole: $$\vec {\tau} = \vec {p} \times \vec {E}$$ …

## UY1: Electric field of a point charge

$$\vec{E} = \lim_{q_{0} \to 0} \frac{1}{q_{0}} \vec{F_{0}}$$ At each point P, the electric field set up by an isolated positive point charge q points directly away from the charge in the same direction as $\hat {r}$. Note: Unit vector $\hat {r}$ points from source point S to field point P. $\hat {r}$ gives direction to $\vec {F}$ and $\vec {E}$. Note …