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A helioscope is an instrument used for observing the sun and sunspots. The helioscope was first used by Benedetto Castelli and refined by Galileo Galilei.

Examples of Fundamental Quantities ; Mass, kilogram, kg ; Electric Current, ampere, A ; Temperature, kelvin, K ; Amount of Substance, mole, Mol.

It is a graph that represents the force that acts on a body in a certain amount of time. Force on the object is represented by the y-axis and time taken by the object is represented by the y axis. The area under the curve indicates the impulse, the change in momentum that the object undergoes.

The kinetic-molecular theory of gases assumes that ideal gas molecules: (1) are constantly moving; (2) have negligible volume; (3) have negligible intermolecular forces; (4) undergo perfectly elastic collisions; and (5) have an average kinetic energy proportional to the ideal gas's absolute temperature.

Archimede's Principle states that a body immersed in a fluid experiences an upthrust equal to the weight of the fluid displaced, and this is fundamental to the equilibrium of a body floating in still water.

The period of a simple pendulum is doubled, when its length is made four times.

cubic and linear expansivity are related by this equation. γ=3\alpha.

If a body moves with uniform retardation, the velocity-time graph is a straight line.

Given Data: L = 10, V = 50, F = 100, I = ? Inductive Reactance [X\(_L\)] = 2\(\pi\)FL → 2 * 3.14 * 100 * 10 X\(_L\) = 6,280 Current[I] = \(\frac{V}{X_L}\) → \(\frac{50}{6280}\) I = 0.0079 ≈ 0.008A

Initial Mass: 512 g, Mass Decayed: \(\frac{7}{8}\) of 512 = 448g, Remaining mass = 512 - 448 = 64g Using, N(t) = No(\(\frac{1}{2}\))\(^{\frac{T}{T1/2}}\) \(\frac{N(t)}{No}\) = (\(\frac{1}{2}\))\(^{\frac{T}{T1/2}}\) \(\frac{64}{512}\) = \(\frac{1}{8}\) = (\(\frac{1}{2}\))\(^{\frac{T}{15}}\) \(\frac{1}{8}\) = (\(\frac{1}{2}\))\(^3\) = (\(\frac{1}{2}\))\(^{\frac{T}{15}}\) equating coefficient 3 = \(\frac{T}{15}\) T = 3 x 15 = 45hours.

Area expansivity(ß) = \(\frac{ A_2 - A_1}{ A_1(\theta_2 - \theta_1})\) Area = \(\frac{\pi d^2}{4}\) \(d_1\) = 50.0cm, \(d_2\) = 50.29cm, \(\theta_1\) = 30ºC, \(\theta_2\) = ? and ß = 2\alpha \(2 \times 1.9 \times 10^{-5}\) = \(\frac{50.29^2 - 50^2}{ 50^2( \theta_2 - 30)}\) \(\theta_2 - 30\) = \(\frac{50.29^2 - 50^2}{ 50^2(2 \times 1.9 \times10^{-5})}\) \(\theta_2\) = 30 + \(\frac{50.29^2 - 50^2}{ 50^2(2 \times 1.9 \times10^{-5})}\) = 335.3 ^\circC note : \(\frac{\pi}{4}\) cancels out.

Properties of intrinsic semiconductors. They; i. Are tetravalent ii. Have thermally generated charge cariers iii. Have equal number of charge carriers iv Have low electrical conductivity/high resistivity.

Dimensions of the angular momentum, K = \(\frac{[K]^{2}}{[m_{1}][r]^{2}} = \frac{[G][m_{1}][m_{2}]}{[r]}\) \(\frac{[k]^{2}}{ML^{2}} = \frac{M^{-1} L^{3} T^{-2}M^{2}}{L}\) [K] = (M\(^{2}\)L\(^4\)T\(^{-2}\))½ \(\therefore\) [k] = ML\(^{2}T^{-1}\) (NOTE: the dimension of E = dimension of gravitational force.)

Calculation of workdone by the force to scratch the string W = ½ ke\(^{2}\) = \(\frac{f^{2}}{2k}\) W = \(\frac{50^{2}}{2 \times 100}\) W = 12.5 J OR e = \(\frac{F}{K} = \frac{50}{100}\) = 0.5m w = ½ = ke\(^{2}\) w = ½ x 100 x 0.5\(^{2}\) W = 12.5 J

(a) Ageostrationary satelite: is an artificial satellite whose period of revolution is equal to the period of rotation of the Earth. OR A satellite whose period of revolution is equal to 24 hrs/ 1 day. (b) Types of lasers i. Gas ii. Solid state iii. Semi-conductor iv. Liquid v. Chemical vi. Fibre