2019 JAMB PHYSICS PAST QUESTIONS AND ANSWERS Leave a Comment / Jamb Physics / By Jamb Tutor Report a question What’s wrong with this question? You cannot submit an empty report. Please add some details. 0% 0 votes, 0 avg Created by Jamb TutorJamb Physics 2019 JAMB PHYSICS PAST QUESTIONS AND ANSWERS 1 / 40 Category: JAMB Physics 2019 1. $$\text{The equation X^{150}_{62} \to Y^{150}_{63} + \beta^{-} + \text{energy, represents:}$$ a) $$\text{Alpha decay.}$$ b) $$\text{Beta-decay.}$$ c) $$\text{Gamma decay.}$$ d) $$\text{Photon emission.}$$ $$\text{Beta-decay occurs when a neutron converts into a proton, emitting a beta particle.}$$ 2 / 40 Category: JAMB Physics 2019 2. $$\text{The ice and steam points of a thermometer are 20 mm and 100 mm respectively. A temperature of 75°C corresponds to Y mm. What is Y?}$$ a) $$\text{100 mm.}$$ b) $$\text{70 mm.}$$ c) $$\text{80 mm.}$$ d) $$\text{60 mm.}$$ $$\text{Using the linear relationship between temperature and length, } Y = 20 + (75 \times \frac{100 – 20}{100}) = 80 \text{ mm.}$$ 3 / 40 Category: JAMB Physics 2019 3. $$\text{When a yellow card is observed through a blue glass, the card would appear as:}$$ a) $$\text{Black.}$$ b) $$\text{Green.}$$ c) $$\text{Red.}$$ d) $$\text{White.}$$ $$\text{Yellow light is absorbed by the blue glass, leaving the card appearing black.}$$ 4 / 40 Category: JAMB Physics 2019 4. $$\text{In a nuclear plant, the final mass of the products is } 6.32 \times 10^{-27} \text{ kg, while the initial mass of the reactant is } 6.30 \times 10^{-27} \text{ kg. The energy released is } 11.25 \text{ meV.}$$ a) $$\text{11.25 meV.}$$ b) $$\text{11.25 MJ.}$$ c) $$\text{12.25 MJ.}$$ d) $$\text{12.25 meV.}$$ $$\text{Using Einstein’s } E = \Delta m c^2 \text{ formula, where } \Delta m = 6.30 – 6.32 \times 10^{-27} \text{ kg.}$$ 5 / 40 Category: JAMB Physics 2019 5. $$\text{A 1.5 kg stone is thrown vertically upward with an initial velocity of } 42 \text{ m/s. What is the potential energy at the highest point?}$$ a) $$\text{3.15 J.}$$ b) $$\text{13.23 J.}$$ c) $$\text{26.46 J.}$$ d) $$\text{63.00 J.}$$ $$\text{At the highest point, all kinetic energy is converted to potential energy. Use } E_p = mgh \text{ with } g = 10 \text{ m/s}^2. E_p = 3.15 \text{ J.}$$ 6 / 40 Category: JAMB Physics 2019 6. $$\text{When two objects P and Q are supplied with the same heat, the temperature change in P is twice that of Q, and the mass of P is half that of Q. The ratio of specific heats of P to Q is:}$$ a) $$\text{1:4.}$$ b) $$\text{4:1.}$$ c) $$\text{1:1.}$$ d) $$\text{2:1.}$$ $$\text{From } Q = mc \Delta T, \text{ solving yields the ratio as } 1:1.}$$ 7 / 40 Category: JAMB Physics 2019 7. $$\text{The correct sequence during the melting of a solid is:}$$ a) $$\text{2, 4, 5.}$$ b) $$\text{2, 3, 6.}$$ c) $$\text{1, 3, 6.}$$ d) $$\text{1, 3, 5.}$$ $$\text{Temperature rises until melting starts, stays constant during melting, and rises again after complete melting.}$$ 8 / 40 Category: JAMB Physics 2019 8. $$\text{A silver spoon and a wooden spoon are at room temperature. The silver spoon feels cooler because:}$$ a) $$\text{Greater density.}$$ b) $$\text{Polishable.}$$ c) $$\text{Less absorbent.}$$ d) $$\text{Better conductor.}$$ $$\text{Silver conducts heat away from the hand faster due to its better thermal conductivity.}$$ 9 / 40 Category: JAMB Physics 2019 9. $$\text{A long jumper leaves the ground at an angle of } 20^{\circ} \text{ with a speed of } 11 \text{ m/s. The horizontal distance covered is:}$$ a) $$\text{0.38 m.}$$ b) $$\text{7.49 m.}$$ c) $$\text{8.45 m.}$$ d) $$\text{0 m.}$$ $$\text{Using the projectile formula, } R = \frac{v^2 \sin(2\theta)}{g}. \text{ Substituting values, } R \approx 7.49 \text{ m.}$$ 10 / 40 Category: JAMB Physics 2019 10. $$\text{The thrust due to hydrostatic pressure on the bottom of a tank with dimensions } 60 \text{ cm } \times 40 \text{ cm } \text{ and water depth of } 30 \text{ cm is:}$$ a) $$\text{8 N.}$$ b) $$\text{12 N.}$$ c) $$\text{720 N.}$$ d) $$\text{24 N.}$$ $$\text{Using } F = \rho g h A, \text{ the thrust is calculated as } F = 720 \text{ N.}$$ 11 / 40 Category: JAMB Physics 2019 11. $$\text{An object of mass 50g is suspended from a spring of force constant } 0.5 \text{ N/m and set into SHM with displacement } 0.3 \text{ m. The period is:}$$ a) $$\text{1.00 s.}$$ b) $$\text{1.99 s.}$$ c) $$\text{3.00 s.}$$ d) $$\text{2.50 s.}$$ $$\text{Using } T = 2 \pi \sqrt{\frac{m}{k}}, \text{ where } m = 0.05 \text{ kg and } k = 0.5 \text{ N/m, solving gives } T \approx 1.99 \text{ s.}$$ 12 / 40 Category: JAMB Physics 2019 12. $$\text{21g of alcohol (density } 0.7 \text{ g/cm}^3) \text{ is mixed with } 10 \text{ g of water. The density of the mixture is:}$$ a) $$\text{780 g/cm}^3$$ b) $$\text{0.78 g/cm}^3$$ c) $$\text{30 g/cm}^3$$ d) $$\text{10 g/cm}^3$$ $$\text{Density is calculated using } \rho = \frac{\text{Total Mass}}{\text{Total Volume}}, \text{ yielding } \rho = 0.78 \text{ g/cm}^3.$$ 13 / 40 Category: JAMB Physics 2019 13. $$\text{Two masses of 50g and 70g are suspended from opposite ends of a meter rule. The center of gravity of the system is:}$$ a) $$\text{50.0 cm.}$$ b) $$\text{52.3 cm.}$$ c) $$\text{70.2 cm.}$$ d) $$\text{80.4 cm.}$$ $$\text{The center of gravity is calculated as the weighted average of distances, yielding } 52.3 \text{ cm.}$$ 14 / 40 Category: JAMB Physics 2019 14. $$\text{A transformer producing } 10 \text{ V from } 240 \text{ V supply has } 60\% \text{ efficiency. If secondary current is } 15 \text{ A, primary current is:}$$ a) $$\text{15.0 A.}$$ b) $$\text{1.04 A.}$$ c) $$\text{16.04 A.}$$ d) $$\text{13.96 A.}$$ $$\text{Using } P_s = P_p \times \text{Efficiency}, \text{ solve for primary current: } I_p = 1.04 \text{ A.}$$ 15 / 40 Category: JAMB Physics 2019 15. $$\text{The acceleration due to gravity:}$$ a) $$\text{Increases with altitude.}$$ b) $$\text{Decreases with altitude.}$$ c) $$\text{Increases with } r^2.$$ d) $$\text{Not altitude dependent.}$$ $$\text{Acceleration due to gravity decreases as altitude increases, because } g \propto \frac{1}{r^2}. $$ 16 / 40 Category: JAMB Physics 2019 16. $$\text{A nail is pulled at an angle of } 30^{\circ} \text{ to the wall with tension } 50 \text{ N. Effective pulling force is:}$$ a) $$\text{25 N.}$$ b) $$\text{25}\sqrt{3}$$ c) $$\text{50 N.}$$ d) $$\text{50}\sqrt{3}$$ $$\text{The horizontal component of force is } F_x = T \cos(30^{\circ}) = 25 \text{ N.}$$ 17 / 40 Category: JAMB Physics 2019 17. $$\text{Electromagnetic waves sensitive to temperature changes are:}$$ a) $$\text{UV rays.}$$ b) $$\text{Gamma rays.}$$ c) $$\text{Infrared rays.}$$ d) $$\text{X-rays.}$$ $$\text{Infrared rays are sensitive to temperature changes and used in thermal imaging.}$$ 18 / 40 Category: JAMB Physics 2019 18. $$\text{A spring-mass system has amplitude } A, \text{ constant } k, \text{ and mass } m. Max potential energy is:}$$ a) $$\text{kA.}$$ b) $$\frac{1}{2}kA^2.$$ c) $$\text{mkA.}$$ d) $$\frac{kA^2}{m}. $$ $$\text{Maximum potential energy is given by } E_p = \frac{1}{2} k A^2. $$ 19 / 40 Category: JAMB Physics 2019 19. $$\text{A transformer connected to } 240 \text{ V a.c has } 500 \text{ turns in primary coil and } 25 \text{ turns in secondary. Induced e.m.f is:}$$ a) $$\text{9.6 V.}$$ b) $$\text{12.0 V.}$$ c) $$\text{120.0 V.}$$ d) $$\text{52.1 V.}$$ $$\text{Using } \frac{V_s}{V_p} = \frac{N_s}{N_p}, \text{ solve for } V_s \approx 12 \text{ V.}$$ 20 / 40 Category: JAMB Physics 2019 20. $$\text{The fundamental frequency of a sonometer wire may be halved by:}$$ a) $$\text{Doubling length.}$$ b) $$\text{Doubling mass.}$$ c) $$\text{Reducing tension.}$$ d) $$\text{Reducing temperature.}$$ $$\text{Doubling the wire length doubles the wavelength, halving frequency.}$$ 21 / 40 Category: JAMB Physics 2019 21. $$\text{A car of mass } 800 \text{ kg attains a speed of } 25 \text{ m/s in 20 seconds. The power developed in the engine is:}$$ a) $$25 \times 10^4 \text{ W.}$$ b) $$50 \times 10^4 \text{ W.}$$ c) $$25 \times 10^6 \text{ W.}$$ d) $$50 \times 10^6 \text{ W.}$$ $$\text{Power is given by } P = \frac{\Delta KE}{\Delta t} = \frac{1}{2}mv^2/t. \text{ Calculation yields } P = 25 \times 10^4 \text{ W.}$$ 22 / 40 Category: JAMB Physics 2019 22. $$\text{When the brakes of a car are applied, the frictional force on the tires:}$$ a) $$\text{Disadvantage (same direction).}$$ b) $$\text{Disadvantage (opposite direction).}$$ c) $$\text{Advantage (same direction).}$$ d) $$\text{Advantage (opposite direction).}$$ $$\text{The friction opposes motion, aiding in stopping the car, making it advantageous.}$$ 23 / 40 Category: JAMB Physics 2019 23. $$\text{A solid weighs } 10.0 \text{ N in air, } 6.0 \text{ N in water, and } 7.0 \text{ N in liquid X. The relative density of liquid X is:}$$ a) $$\frac{5}{3}. $$ b) $$\frac{4}{3}. $$ c) $$\frac{3}{4}. $$ d) $$\frac{7}{10}. $$ $$\text{Relative density } = \frac{W_{\text{apparent in X}}}{W_{\text{apparent in water}}} = \frac{3}{4}. $$ 24 / 40 Category: JAMB Physics 2019 24. $$\text{When the temperature of a liquid increases, its surface tension:}$$ a) $$\text{Decreases.}$$ b) $$\text{Increases.}$$ c) $$\text{Remains constant.}$$ d) $$\text{Increases then decreases.}$$ $$\text{Surface tension decreases with increasing temperature because cohesive forces weaken.}$$ 25 / 40 Category: JAMB Physics 2019 25. $$\text{A gas has initial volume } V_0 \text{ and pressure } P_0. \text{ Compressed to } \frac{V_0}{5}, \text{ the pressure is:}$$ a) $$\frac{P_0}{5}. $$ b) $$\frac{4P_0}{5}. $$ c) $$P_0. $$ d) $$5P_0. $$ $$\text{From Boyle’s law } P_1V_1 = P_2V_2, \text{ solve for } P_2 = 5P_0. $$ 26 / 40 Category: JAMB Physics 2019 26. $$\text{Waterfall is } 420 \text{ m high; calculate the temperature difference if no heat is lost.}$$ a) $$10^{\circ}C. $$ b) $$42^{\circ}C. $$ c) $$4.2^{\circ}C. $$ d) $$1^{\circ}C. $$ $$\text{Using } \Delta T = \frac{mgh}{mc}, \text{ solve to find } \Delta T = 1^{\circ}C.$$ 27 / 40 Category: JAMB Physics 2019 27. $$\text{A body in neutral equilibrium is displaced slightly. It will:}$$ a) $$\text{Rest in a new position.}$$ b) $$\text{Return to original position.}$$ c) $$\text{Remain in displaced position.}$$ d) $$\text{Move further from original position.}$$ $$\text{In neutral equilibrium, the center of gravity remains at the same height, and the body rests at any position.}$$ 28 / 40 Category: JAMB Physics 2019 28. $$\text{A spring of length } 5m \text{ extends } 0.04m \text{ under load. Applied force } 16N \text{ gives extension:}$$ a) $$\text{0.04m.}$$ b) $$\text{0.12m.}$$ c) $$\text{0.01m.}$$ d) $$\text{0.08m.}$$ $$\text{Using Hooke’s law, } \Delta L = \frac{F}{k}, \text{ solve for } \Delta L = 0.08m.$$ 29 / 40 Category: JAMB Physics 2019 29. $$\text{Which of the following has negligible mass?}$$ a) $$\text{Protons.}$$ b) $$\text{Gamma rays.}$$ c) $$\text{Beta particles.}$$ d) $$\text{Alpha particles.}$$ $$\text{Gamma rays are photons with negligible mass and high energy.}$$ 30 / 40 Category: JAMB Physics 2019 30. $$\text{Energy loss due to eddy currents can be minimized by:}$$ a) $$\text{High resistance wires.}$$ b) $$\text{Insulated soft iron wires.}$$ c) $$\text{Low resistance wires.}$$ d) $$\text{Turns of wires.}$$ $$\text{Eddy currents are minimized using laminated cores or soft insulated iron wires.}$$ 31 / 40 Category: JAMB Physics 2019 31. $$\text{Upthrust on an object of volume } 50 \text{ cm}^3 \text{ in liquid density } 10^3 \text{ kgm}^{-3}:$$ a) $$\text{0.8N.}$$ b) $$\text{2.5N.}$$ c) $$\text{0.5N.}$$ d) $$\text{1.0N.}$$ $$\text{Upthrust } = V \times \rho \times g. \text{ Solving gives } 0.5 \text{ N.}$$ 32 / 40 Category: JAMB Physics 2019 32. $$\text{A white screen illuminated by red and green light appears as:}$$ a) $$\text{Red.}$$ b) $$\text{Purple.}$$ c) $$\text{Yellow.}$$ d) $$\text{Green.}$$ $$\text{Red and green light combine to form yellow, which appears on the screen.}$$ 33 / 40 Category: JAMB Physics 2019 33. $$\text{Electric field intensity between plates of } 6.5 \text{ V and separation } 35 \text{ cm:}$$ a) $$\text{18.57 NC}^{-1}. $$ b) $$\text{53.06 NC}^{-1}. $$ c) $$\text{2.28 NC}^{-1}. $$ d) $$\text{0.80 NC}^{-1}. $$ $$\text{Field intensity } = \frac{V}{d} = \frac{6.5}{0.35}. \text{ Solve for } E = 18.57 \text{ NC}^{-1}. $$ 34 / 40 Category: JAMB Physics 2019 34. $$\text{Object distance reduced by } 9.2 \text{ cm; find new distance from plane mirror:}$$ a) $$\text{17.50 cm.}$$ b) $$\text{15.50 cm.}$$ c) $$\text{18.50 cm.}$$ d) $$\text{16.50 cm.}$$ $$\text{The total distance is halved. Calculation gives } 15.50 \text{ cm.}$$ 35 / 40 Category: JAMB Physics 2019 35. $$\text{Potential energy of } 10 \text{ kg object at height } 10 \text{ m above ground:}$$ a) $$\text{10,000 J.}$$ b) $$\text{5,000 J.}$$ c) $$\text{100 J.}$$ d) $$\text{1,000 J.}$$ $$\text{Potential energy } = mgh. \text{ Substitution gives } 10,000 \text{ J.}$$ 36 / 40 Category: JAMB Physics 2019 36. $$\text{Volume of gas changes from } 10 \text{ cm}^3 \text{ at } 400 \text{ cmHg to pressure } 200 \text{ cmHg; find new volume:}$$ a) $$\text{30 cm}^3. $$ b) $$\text{40 cm}^3. $$ c) $$\text{50 cm}^3. $$ d) $$\text{20 cm}^3. $$ $$\text{From Boyle’s law, } P_1V_1 = P_2V_2. \text{ Solve for } V_2 = 20 \text{ cm}^3. $$ 37 / 40 Category: JAMB Physics 2019 37. $$\text{Product PV of gas represents:}$$ a) $$\text{Impulse.}$$ b) $$\text{Power.}$$ c) $$\text{Force.}$$ d) $$\text{Work.}$$ $$\text{Pressure } \times \text{ volume gives work, as it has the same unit (Joule).}$$ 38 / 40 Category: JAMB Physics 2019 38. $$\text{Cost of running } 7 \times 40 \text{ W lamps and } 5 \times 80 \text{ W lamps for } 12 \text{ hrs; energy costs ₦7.00/kWh:}$$ a) $$\text{₦80.00.}$$ b) $$\text{₦45.36.}$$ c) $$\text{₦65.00.}$$ d) $$\text{₦57.12.}$$ $$ \text{Total power} = 7 \times 40 + 5 \times 80. \\ \text{Calculate total cost as } \frac{\text{Power} \times \text{time}}{1000} \times \text{cost per kWh}. \\ \text{Result is } ₦57.12. $$ 39 / 40 Category: JAMB Physics 2019 39. $$\text{Velocity ratio of inclined plane is given by:}$$ a) $$\frac{1}{\sin \theta}. $$ b) $$\sin \theta. $$ c) $$\cos \theta. $$ d) $$\tan \theta. $$ $$\text{The velocity ratio is } \frac{1}{\sin \theta}. $$ 40 / 40 Category: JAMB Physics 2019 40. $$\text{An object is placed beyond the center of a concave mirror. The image forms:}$$ a) $$\text{At infinity.}$$ b) $$\text{At the center.}$$ c) $$\text{At the focus.}$$ d) $$\text{Between center and focus.}$$ $$\text{For objects beyond the center, the image forms between the center of curvature and the focus, inverted and reduced.}$$ Your score is The average score is 0% LinkedIn Facebook Twitter VKontakte 0% Restart quiz Anonymous feedback Send feedback
