Basic and Applied Science Physics SEM-I & II

The force per unit area that acts perpendicular to the surface of a material, causing a change in its length.

The energy required to remove an electron from the surface of a metal.

The ratio of the maximum load a material can withstand before breaking to its original cross-sectional area.

The time it takes for a complete oscillation in a simple harmonic motion (SHM).

The rate at which work is done.

The energy possessed by an object due to its motion. It depends on the object's mass and velocity.

The energy transferred per unit charge through an electric circuit.

The energy of a photon, which is directly proportional to its frequency.

In a forward-biased p-n junction diode, this voltage is the threshold at which the diode starts conducting significantly, allowing current to flow through it.

A semiconductor material in its purest form, without intentional impurities added. It has a moderate conductivity, lying between that of a conductor and an insulator.

A diode that allows current to flow in one direction only when forward-biased. It acts as a closed switch when forward-biased, and an open switch when reverse-biased.

The state of a diode where the voltage across the diode is reversed. No current flows through the diode in this state, making it act like an open switch.

In a reverse-biased p-n junction diode, the resistance is extremely high because very little current flows through the diode.

The point at which a diode is fully conducting in the forward-biased direction.

A component that restricts the flow of electric current. It's essential for controlling the current in circuits.

A material that prevents the flow of electric current. Imagine it as blocking the path of electrons.

The energy of an X-ray emitted is directly proportional to the frequency of the X-ray, and inversely proportional to its wavelength. Higher frequency means higher energy.

The minimum energy required to remove an electron from a metal surface is called the work function. This energy is related to the wavelength of light by the photoelectric effect.

The period of a simple harmonic motion is the time taken for one complete oscillation. It's inversely proportional to the angular frequency of the motion.

The frequency of a simple harmonic motion is the number of oscillations completed per second. It's the inverse of the period.

The time of flight of a projectile is the total time it spends in the air. It's determined by the initial vertical velocity and the acceleration due to gravity.

The ratio of the change in length of a wire to its original length is directly proportional to the stress applied, and inversely proportional to the Young's modulus of the material.

The breakdown voltage of a diode is the minimum voltage that allows the diode to conduct significantly. Below this voltage, the diode acts as an open switch, effectively blocking current flow.

A germanium diode has a lower threshold voltage, typically around 0.3-0.4V, compared to silicon diodes. This means it starts conducting at a lower voltage.

Series resistance is the total resistance when resistors are connected one after the other. Parallel resistance calculates the total resistance when resistors are connected side by side.

The operating voltage of an X-ray tube is the voltage applied across the tube to accelerate electrons, producing X-rays. Higher voltage leads to higher energy X-rays with shorter wavelengths.

The threshold wavelength is the longest wavelength that can eject an electron from a metal surface. It's related to the minimum energy required for the photoelectric effect.

When a wave travels from one medium to another, its wavelength changes. The speed of the wave also changes, but not necessarily by the same factor. Often, the frequency of the wave remains constant.

The elongation of a wire under a load is proportional to the applied force, the length of the wire, and inversely proportional to the cross-sectional area (and thus the radius).

The wavelength of a wave is related to its velocity and frequency by the equation: wavelength = velocity / frequency. You can calculate wavelength using this equation.

Boyle's law states that the pressure and volume of a gas are inversely proportional at a constant temperature. This means that if the volume of a gas is increased, the pressure will decrease, and vice versa.

The temperature gradient is the rate at which temperature changes over a distance. In this case, the temperature decreases by 3°C for every centimeter along the rod.

Once the voltage applied to a forward-biased diode exceeds the knee voltage, the diode starts conducting significantly. This means the current flowing through the diode increases rapidly.

Intrinsic semiconductors like silicon or germanium have four electrons in their outer shell, which is called the valence shell.

When a p-n junction diode is reverse biased, it acts like an open switch, meaning it blocks the flow of current. This is because the reverse bias voltage pushes the majority charge carriers away from the junction, creating a depletion region with high resistance.

In reverse bias, the diode's resistance is very high, preventing most of the current from flowing. This is because the reverse bias voltage makes it difficult for charge carriers to cross the junction.

If the operating voltage is below the breakdown voltage, the diode will act as an open switch, blocking the flow of current. It won't get damaged because the voltage is not high enough to cause a breakdown.

When a voltage of 0.4V is applied across a germanium diode, the diode will act as a conductor, allowing current to flow. This is because the voltage is sufficient to overcome the diode's forward voltage drop, and the diode starts conducting.