Category: Physics

Fluorescent Lamp

Fluorescent Lamp: The above figure shows the constructional details of the Fluorescent Lamp. It consists of a long glass tube which is internally coated with a suitable amount of fluorescent powder. A small amount of mercury along with a little quantity of argon gas is also filled in the tube. There are two electrodes A and …

Mercury Vapour Lamp

Mercury Vapour Lamp: Construction- The lamp consists of two bulbs, an inner bulb and an outer bulb. The electric discharge takes place in the inner bulb. The outer bulb protects the inner bulb and reduces the loss of heat. The inner bulb consists of a small amount of mercury and argon gas. The two electrodes E …

Sodium Vapour Lamp

Sodium Vapour Lamp: Construction: It consists of two glass tubes, an outer glass tube and an inner glass tube. The inner glass tube contains two electrodes. Sodium along with a small quantity of neon or argon gas is filled in an inner tube to make discharge self-starting. Sodium vapour is chemically very active. The glass of …

Dispersion of Light

Dispersion of Light: When a narrow beam of white light is allowed to pass through a prism, a beautiful pattern of colours appears on the screen, this shows that white light consists of a number of components each of which causes a particular sensation of colour. We know that light travels in waves and the components …

Extrinsic Semiconductor

Extrinsic Semiconductor: Definition- A semi-conductor with suitable impurity atoms added to it, is called an extrinsic semiconductor. It is of two types- N-Type Semiconductor. P-Type Semiconductor. N-Type Semiconductor: When atoms from Group V of the periodic table (example- As, P etc.) are added to a pure semiconductor, we get an N-type semiconductor. The group V, atoms …

Maximum Power Theorem

Maximum Power Theorem: Statement: It states that the output power will be maximum, if external resistance R, connected to the source is equal to the internal resistance of the source. Proof: Let us consider an electric circuit having battery E, key K and external resistance R, all connected in series. Let ‘r’ be the internal resistance …

Variation of Thermo EMF with Temperature

Variation of Thermo EMF with Temperature: Let us take a copper-iron thermocouple, with a galvanometer G in the circuit. Keep the temperature of the cold junction fixed at 0°C. Now the temperature of hot junction A is gradually changed (increased) and at each time thermo e.m.f is noted. After then, a graph is plotted between the …

Hysteresis Loss

Hysteresis Loss: According to the molecular theory of magnetism groups of molecules acts like elementary magnets, which are magnetized to saturation. This magnetism is developed because of the magnetic effect of electron spins, which are known as ‘domains’. When the material is unmagnetized, the axis of the different domains are in various direction. Thus the resultant …

Potential Energy of Magnetic Dipole in Magnetic Field

Potential Energy of Magnetic Dipole in Magnetic Field: Potential Energy of dipole in magnetic field is defined as the energy possessed by the dipole due to its position in the field. Electric Current Shapes of Atomic Orbitals Resistance and Resistivity of a Conductor Silicates and its Classification Applications of Electrolysis Hydrogen-Oxygen Fuel Cell Lenz’s Law The …

Current Loop as Magnetic Dipole

Current Loop as Magnetic Dipole: Consider a plane loop of wire carrying current. Looking at the upper face, the current is anti-clockwise. Therefore, the upper face will become N-pole. Looking at the lower face of the loop, the current is clockwise. Therefore, the lower face will become the South pole. Hence the current-carrying loop behaves as …