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Electrical conduction of gas is applied in: (i) The identification of gases (ii) Lighting/fluorescent tubes (iii) Advertising industry/Neon signs (iv) Cathode ray oscilloscope/T.V. tubes

For the combination in series; ⇒R1 = 35k\Omega + 40k\Omega = 75k\Omega R is combined with 75k\Omega in parallel to give 25k\Omega = \(\frac{1}{R_eq}\) = \(\frac{1}{R}\) + \(\frac{1}{R}\) = \(\frac{1}{25}\) = \(\frac{1}{R}\) + \(\frac{1}{75}\) = \(\frac{1}{25}\) - \(\frac{1}{75}\) + \(\frac{1}{R}\) = \(\frac{3-1}{75}\) = \(\frac{1}{R}\) = \(\frac{2}{75}\) = \(\frac{1}{R}\) = \(\frac{75}{2}\) = R ; R = 37.5k \Omega

The electrolyte used in the Nickel-Iron (NiFe) accumulator is potassium hydroxide solution. It is a non-flammable, non-toxic, and relatively stable electrolyte. It is also a good conductor of electricity, which is important for the operation of the battery.

Rubber is a good insulator because it does not allow electrons to flow through it easily. Copper, silver, and water are all good conductors of electricity.

An incandescent light source is a type of light source that produces light by heating a material until it glows. The material that is heated is usually a metal, such as tungsten. Fluorescent lamps, LED lamps, and neon lamps are all examples of non-incandescent light sources. Fluorescent lamps produce light by passing an electric current through a gas, which causes the gas to emit ultraviolet light. The ultraviolet light then causes a coating on the inside of the lamp to fluoresce, which produces visible light. LED lamps produce light by passing an electric current through a semiconductor material, which causes the material to emit photons. The photons then produce visible light. Neon lamps produce light by passing an electric current through a gas, which causes the gas to emit visible light.

\(V_L\)=60 V ,\(V_C\) = 120 V , \(V_R\) =30V ;V = ? ; \(V^2\) = \(V_R^2\) + \(V_L\) - \(V_C^2\) = \(V^2\) = \(30^2\) + \(60 - 120^2\) = \(V^2\) = 900 + 3600 = \(V^2\) = 4500 = V = \sqrt4500 = 67V

Resonance in an AC circuit occurs when the inductive reactance (XL) is equal to the capacitive reactance (XC). This is because at this point, the two reactances cancel each other out, leaving only the resistance of the circuit. As a result, the impedance of the circuit is minimized.

The stopping potential is the voltage that is required to stop the emitted photoelectrons from reaching the anode. When the frequency of the light is increased, the kinetic energy of the emitted photoelectrons also increases. This means that a higher stopping potential will be required to stop the photoelectrons from reaching the anode.

An intrinsic semiconductor, also called an undoped semiconductor, is a pure semiconductor. In intrinsic semiconductors the number of excited electrons and the number of holes are equal: n = p

\(T_ {^1/_2}\) = 12 days ;V=? \(T_ {^1/_2}\) = \(\frac{0.693}{γ}\) ⇒γ ⇒\(\frac{0.693}{t_{^1/_2}}\) ⇒γ =\(\frac{0.693}{12}\) ⇒γ= 0.05775 \(day^{-1}\)

Nuclear fusion is the process in which lighter nuclei are combined to form heavier ones. Matter lost in this process is converted into energy. The energy produced inside the stars is due to the process of nuclear fusion.

The penetrating power of alpha rays, beta rays, and gamma rays varies greatly. Alpha particles can be blocked by a few pieces of paper. Beta particles pass through paper but are stopped by aluminum foil. Gamma rays are the most difficult to stop and require concrete, lead, or other heavy shielding to block them. Therefore, X = γ-ray; Y = \alpha-particle; Z = \beta-particle

The Bohr model is a model of the atom that describes electrons as orbiting the nucleus in specific energy levels. This model was developed by Niels Bohr in 1913 and it is based on the work of Max Planck and Albert Einstein. The Rutherford model, the Thomson model, and the Dalton model are all older models of the atom that are not as accurate as the Bohr model.

Classical mechanics is a branch of physics that deals with the motion of macroscopic objects. It is based on the principles of Newton's laws of motion and is not considered to be part of elementary modern physics. The other three options, quantum mechanics, special relativity, and nuclear physics, are all considered to be part of elementary modern physics because they deal with the behavior of matter and energy at the atomic and subatomic levels.

As light ray enters a drop of water the light is refracted at the surface and at the end of the drop, it is totally internally reflected in which the reflected light returns to the front surface, where it again undergoes refraction as it moves from water to air. The result of this is a dispersed light of colours of different wavelengths.