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Recall V = F \times \(\lambda\) = 260 \times 1.29 = 335.4ms\(^{-1}\) Echo time = \(\frac{2}{2}\) = 1 sec Distance = v x t = 335.4 x 1 = 335.4m

Fuse wires have a low melting point so that if a huge amount of current is passed through it to any appliance than that wire would melt and stop the appliance from getting damaged by not letting the current pass any further.

P = 40W R = 90W V = ? P = \(\frac{V^2}{R}\) V\(^2\) = PR = 40 x 90 V\(^2\) = 3000 V = \sqrt3600 V = 60N

In case of small drops of mercury, the gravitational potential energy is negligible in comparison to the potential energy due to surface tension.Consequently, to keep the drop in equilibrium, the mercury drop’s surface tends to contract so that its surface area will be the least for a sphere and the drops will be spherical. But in the case of bigger drops of mercury, the potential energy due to gravity is predominant over the potential energy due to surface tension.Consequently, to keep equilibrium , the mercury drop tends to assume minimum potential energy as possible, the drop becomes oval in shape and lower center of gravity.

Water 1 => M = 150g = 0.15kg, \theta\(_2\) = 60\(^o\)C; \theta\(_1\) = \theta Q\(_1\) = MC (\theta\(_2\) – \theta\(_1\)) = 0.15C (60 - \theta) Water 2 => M = 300g = 0.3kg \theta1 = 20\(^o\)C, \theta\(_2\) = \theta Q2 = MC (\theta\(_2\) – \theta\(_1\)) = 0.3C (\theta – 20) Combining Q1 and Q2 0.15C (60 - \theta) = 0.3C (\theta – 20) 9 – 0.15\theta = 0.3\theta – 6 0.3\theta + 0.15\theta = 9 + 6 0.45 \theta = 15 \theta = 33.33\(^o\)C

Brownian motion, also called Brownian movement, any of various physical phenomena in which some quantity is constantly undergoing small, random fluctuations. If a number of particles subject to Brownian motion are present in a given medium and there is no preferred direction for the random oscillations, then over a period of time the particles will tend to be spread evenly throughout the medium.

using the formular : Moment = Force \times Distance 5 X 0 = 0Nm

X = \(\frac{4}{3}\) r = ? Shell’s law:. = \(\frac{Sin i^0}{ Sin r^0}\) = \(\frac{Sin 30^0}{Sin r^0}\) Sin\(r^0\) = \(\frac{3 Sin 30^0}{4}\) Sin \(r^0\) = 0.375 R \(^o\) = Sin-1 (0.375) R \(^o\) = 22.02 \(^o\) R \(^o\) = 22 \(^o\)

Power = 1kw=100W Time = 2mins = 2 \times 60 = 120secs Energy = power \times time 1000 \times 120 = 120,000J Energy = mc(\theta\(_2\) – \theta\(_1\)) 120,000 = 2 \times 4000(\theta\(_2\) – \theta\(_1\)) \theta2 = 30 + 15 = 45 \(^o\) C

Earth acts as a ground of zero potential. So when a positively charged conductor is connected to the earth, positive charge flows into the earth and as a result, electrons flow from earth to the conductor.

Thermonuclear fusion is the process that occurs when two atoms combine to make a larger atom, creating a whole lot of energy. Fusion already happens naturally in stars — including the sun — when intense pressure and heat fuse hydrogen atoms together, generating helium and energy. Thermionic emission: thermally induced flow of charge Nuclear fission: nuclear reaction or a radioactive decay process Photoelectric emission: emission of electrons or other free carriers when light shines on a material

Y – Ray is a penetrating electro-magnetic radiation. \alpha – particle is produced in the process of alpha decay. Neutron is a sub-atomic particle.

Radiation refers to the transmission of energy as electromagnetic radiation from its emission at a heated surface to its absorption on another surface, a process requiring no medium to convey the energy. Conduction is the transferring of heat by direct contact. Convection is transferring heat through the motions of fluids (gases and liquids).

Conduction: the flow of internal energy from a region of higher temperature to lower temperature Convection: heat transfer due to bulk movement of molecules within fluids Expansion: the action of becoming larger or more extensive

Viscosity, resistance of a fluid (liquid or gas) to a change in shape, or movement of neighboring portions relative to one another. Viscosity denotes opposition to flow. The reciprocal of the viscosity is called the fluidity, a measure of the ease of flow. Molasses, for example, has a greater viscosity than water. Because part of a fluid that is forced to move carries along to some extent adjacent parts, viscosity may be thought of as internal friction between the molecules; such friction opposes the development of velocity differences within a fluid. Viscosity is a major factor in determining the forces that must be overcome when fluids are used in lubrication and transported in pipelines. It controls the liquid flow in such processes as spraying, injection molding, and surface coating.