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No expanded working has been attached for this question yet. The verified answer is Option B.

No expanded working has been attached for this question yet. The verified answer is Option C.

Beat = f2 - f1 = 270 - 258 = 12Hz

Quality Dimensions a) Impulse b) Acceleration c) Work MLT\(^{-1}\) LT\(^{-2}\) ML\(^2\)T\(^{-2}\)

The components of velocity at maximum height are: Vy = 0 Vx = UCos \(\theta\) = 20 Cos 40^\circ =15.32ms\(^{-1}\)

Materials used to demonstrate Brownian motion are: Pollen grains, dust particles, smoke particles, potassium permanganate cystals, carbon particles, etc.

F = evB sin \(\theta\) V = \(\frac{F}{evB sin \theta} = \frac{9.6 \times 10^{12}}{1.6 \times 10^{-19} \times 0.12 sin 90^o}\) = \(\frac{9.6 \times 10^{-12}}{1.6 x 10^{-19} \times 0.12 \times 1}\) = 5.0 x 10\(^8 ms{-1}\)

Uses rockets are: — for space travel — for space exploration — for warfare — for launching of artificial satellites into orbits — for entertainment, that is fireworks

(a) Doping is the introduction of impurity atoms into a semicondoctor (b) Doping increases the conductivity of a semicondoctor by increasing the number of chargers or electron or holes.

The cathode ray tube components are: X = Filament or heater or cathode Y = Anode Z = Plates or deflectors.

(a) Net force is the effective or resultant force resulting from the actions of a system of forces on a body. (b) The principle ofconservation of linear momentum explains that in an isolated or closed system of colliding bodies the total linear momentum in a fixed direction remains constant, e.g. the recoil of gun, colliding trolleys, rocket propulsion, etc. (c) V\(_1^2\) = \(U_1^2 + 2gh_1\) = 0 + 2 x 10 x 2 = 40 \(V_1 = \sqrt{40}\) = 6.325m/s \(v_2^2 = u_2^2 - 2gh_2\) O = \(U^2_2\) - 2 x 10 x 1.8 u = \(\sqrt{36}\) = 6ms\(^{-1}\) Impulse Change in momentun mv\(_1\) - (-mu\(_2\)) = m (v\(_1\) + u\(_2\)) = 0.2(6.325 + 6.000) = 2.46 Ns (d) v = \(\omega \sqrt{r^2 - y^2}\) 2\(\pi\)f\(\sqrt{r^2 - y^2}\) 2 = 2 x 3.14 x 5 x \(\sqrt{r^2 - 0.1^2}\) r = 0.12m (ii) Vmax = \(\omega\)r = 2\(\pi\)fr = 2 x 3.142 x 5 x 0.12 = 3,77 m/s (iii) P.E = \(\frac{1}{2}m \omega^2e^2 = \times \frac{1}{2}m(2 \pi f)^2r^2\) = \(\frac{1}{2} \times 0.02(2 \times 3.142 \times 5)^2 \times (0.12)^2\) = 1.42 x 10\(^{-1}J\)

(a)(i) Thermal equilibrium is a condition in which two bodies in contact have no net flow of heat between them. (ii) Fundamental interval is the difference in temperature between the lower fixed point, i.e. temperature of melting ice at standard atmospheric pressure and that upper fixed point, i.e. temperature of steam at standard atmospheric pressure. (b) Uses of hydraulic press are:- -Compressing metal sheets; -Compressing soft materials into bales; -Compressing paper in printing industries; -Lifting of objects. (c) The material used to reset the steel index in the six's maximum and minimum thermometer is magnet. (d)(i) Heat lost by mixture = Heat gained by water + Heat gained by aluminium. M\(_mC_w\Delta \theta_m\) + C\(_a\Delta\theta_a\) 0.3 x C\(_m\) x (85 - 40) = 0.5 x 4200 (40 - 26) + 90 (40 - 26) 13.5 C\(_m\) = 29400 + 1260 C\(_m\) = \(\frac{30660}{13.5}\) = 2271.1 Jkg\(^{-1}\)K\(^{-1}\) (ii) (\(\alpha\)) The bottle losses heat through conduction and convection. (\(\beta\)) Heat exchanger in: Incubation, refriaeration, air-conditioning, sewage treatment, cooling byradiators, generation of electricity, etc.

(a) Critical angle is defined as the angle of incidence in the denser medium for which the angle of refraction in the less dense medium is 90^\circ. (b) Antinodes are created in a stationary wave when an incident and its reflected waves are superposed and 180^\circ out of phase. (c) n = \(\frac{Sin\frac{(A + Dm)}{2}}{\sin (\frac{A}{2})}\) = \(\frac{Sin\frac{(60 + 46.2)}{2}}{\sin (\frac{60}{2})}\) = \(\frac{sin 53.1}{sin 30}\) = 1.6 (d) No image is obtained on the screen because - Object, screen and mirror are not coaxial; - Object is placed at focal point of mirror; - Object is placed between the focus and the pole; - Screen is located at a distance less than or greater than actual image distance. (e) (i) \(\frac{1}{u} + \frac{1}{v} = \frac{1}{f}\) \(\frac{1}{v} = \frac{1}{f} - \frac{1}{u} = \frac{1}{30} - \frac{1}{7}\) = \(\frac{5 - 2}{150} = \frac{3}{150}\) U = 75 + 25 = 100cm \(\frac{1}{u} + \frac{1}{v} = \frac{1}{f}\) \(\frac{1}{100} + \frac{1}{50} = \frac{1}{50} = \frac{1}{50}\) f = 50cm

a) Dielectric strength is the maximum potential gradient or electric field strength an insulator can withstand without breaking down. It is measured in Vmm\(^{-1}\) or Vm\(^{-1}\). (b)(i) The wave is infra-red wave. (ii) Suitable detector can be -Infra-red camera; -Thermopile; -Bolometer or -Photographic film. (iii) Source of the wave can be - Hot bodies or sun (c) E = \(\frac{F}{q} = \frac{W}{q}\) W =mF = Eq = 1200 x 1.0 x 10\(^{-19}\) = 1200 x 1.0 x 10\(^{-19}\)N (d) X\(_L\) = 1.2\(\pi fL\) = 2 x 3.142 x 50 x 0.50 = 15.7\(\Omega\) X\(_c\) \(\frac{1}{2 \pi fL}\) = \(\frac{1}{2 \times 3.14 \times 50 \times 25 \times 10^{-16}}\) = 127.4 \(\Omega\) (i) Z = \(\sqrt{R^2 + (X_1 - X_c)^2}\) = \(\sqrt{100^2 + (127.4 - 15.7)^2}\) = 149.9\(\Omega\) (ii) I \(\frac{V}{Z} = \frac{220}{149.9}\) = 1.47A

(a)(i) Mass defect is the difference between the mass of a nucleus and the total mass of its nucleons. It expressed in atomic mass unit (a.m.u.). It is also a measure of binding energy. Mass defect = total mass of nucleus – mass of nucleons. (ii) Binding energy is the work done or energy needed to separate the nucleons in a nucleus. It is measured in eV or Joules (J). (b)(i) The effect of decreasing the speed of a photoelectron on: (\(\alpha\)) wavelength --> wavelength increases. (\(\beta\)) energy ---> energy decreases. (ii) \(\lambda = \frac{h}{mv}\) = \(\frac{6.6 \times 10^{-34}}{4.4 \times 10^{-2} \times 10^{-16}}\)m (c) Pairs of isotopes in the figure are; \(^{208}_{82}Pb\) and \(^{212}_{82}Pb\) or \(^{212}_{84}Po\) and \(^{216}_{84}Po\) or \(^{224}_{88}Ra\) and \(^{288}_{88}Ra\) or \(^{288}_{90}Th\) and \(^{232}_{90}Th\) (ii) The series started with isotopes \(^{232}_{90}Th\) (iii) Nuclear equation for; \(\alpha\)Alpha decay \(^{232}_{90}Th\) \(\to\) \(^{228}_{88}Ra\) + \(^{4}_{2}He\) + Energy; \(^{228}_{90}Th\) \(\to\) \(^{22}_{88}Ra\) + \(^{4}_{2}He\) + Energy; \(^{224}_{88}Ra\) \(\to\) \(^{220}_{86}Rn\) + \(^{4}_{2}He\) + Energy; \(^{212}_{84}Po\) \(\to\) \(^{208}_{82}Pb\) + \(^{4}_{2}He\) + Energy; \(^{216}_{84}Po\) \(\to\) \(^{212}_{82}Pb\) + \(^{4}_{2}He\) + Energy; \(^{212}_{84}Rn\) \(\to\) \(^{208}_{82}Po\) + \(^{4}_{2}He\) + Energy; \(^{220}_{84}Rn\) \(\to\) \(^{216}_{84}Po\) + \(^{4}_{2}He\) + Energy; \(^{216}_{84}Rn\) \(\to\) \(^{212}_{82}Pb\) + \(^{4}_{2}He\) + Energy; (\(\beta\)) Beta decay \(^{224}_{88}Ra\) \(\to\) \(^{224}_{89}Ac\) + \(^{o}_{-1}e\) + Energy; \(^{228}_{88}Ac\) \(\to\) \(^{228}_{90}Ac\) + \(^{o}_{-1}e\) + Energy; \(^{212}_{82}Pb\) \(\to\) \(^{212}_{83}Bi\) + \(^{o}_{-1}e\) + Energy; \(^{212}_{83}Ra\) \(\to\) \(^{212}_{84}Ac\) + \(^{o}_{-1}e\) + Energy;