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% Created by Jamb TutorJamb Physics 2019 JAMB PHYSICS PAST QUESTIONS AND ANSWERS 1 / 40 Category: JAMB Physics 2019 1. The equation ${X^{150}{62}} \to {Y^{150}{63}} + \beta^{-}$ + energy, represents: a) Alpha decay. b) Beta-decay. c) Gamma decay. d) Photon emission. Beta-decay occurs when a neutron converts into a proton, emitting a beta particle. 2 / 40 Category: JAMB Physics 2019 2. 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) 100 mm. b) 70 mm. c) 80 mm. d) 60 mm. Using the linear relationship between temperature and length, ${Y = 20 + (75 \times \frac{100 – 20}{100})} = 80$ mm. 3 / 40 Category: JAMB Physics 2019 3. When a yellow card is observed through a blue glass, the card would appear as: a) Black. b) Green. c) Red. d) White. Yellow light is absorbed by the blue glass, leaving the card appearing black. 4 / 40 Category: JAMB Physics 2019 4. In a nuclear plant, the final mass of the products is ${6.32 \times 10^{-27}}$ kg, while the initial mass of the reactant is ${6.30 \times 10^{-27}}$ kg. The energy released is 11.25 meV. a) 11.25 meV. b) 11.25 MJ. c) 12.25 MJ. d) 12.25 meV. Using Einstein’s ${E = \Delta m c^2}$ formula, where ${\Delta m = 6.30 – 6.32 \times 10^{-27}}$ kg. 5 / 40 Category: JAMB Physics 2019 5. A 1.5 kg stone is thrown vertically upward with an initial velocity of 42 m/s. What is the potential energy at the highest point? a) 3.15 J. b) 13.23 J. c) 26.46 J. d) 63.00 J. At the highest point, all kinetic energy is converted to potential energy. Use ${E_p = mgh}$ with ${g = 10}$ m/s${^2}$. ${E_p = 3.15}$ J. 6 / 40 Category: JAMB Physics 2019 6. 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) 1:04 b) 4:01 c) 1:01 d) 2:01 From ${Q = mc \Delta T}$, solving yields the ratio as 1:1. 7 / 40 Category: JAMB Physics 2019 7. The correct sequence during the melting of a solid is: a) 2, 4, 5. b) 2, 3, 6. c) 1, 3, 6. d) 1, 3, 5. Temperature rises until melting starts, stays constant during melting, and rises again after complete melting. 8 / 40 Category: JAMB Physics 2019 8. A silver spoon and a wooden spoon are at room temperature. The silver spoon feels cooler because: a) Greater density. b) Polishable. c) Less absorbent. d) Better conductor. Silver conducts heat away from the hand faster due to its better thermal conductivity. 9 / 40 Category: JAMB Physics 2019 9. A long jumper leaves the ground at an angle of 20° with a speed of 11 m/s. The horizontal distance covered is: a) 0.38 m. b) 7.49 m. c) 8.45 m. d) 0 m. Using the projectile formula, ${R = \frac{v^2 \sin(2\theta)}{g}}$. Substituting values, ${R \approx 7.49}$ m. 10 / 40 Category: JAMB Physics 2019 10. The thrust due to hydrostatic pressure on the bottom of a tank with dimensions 60 cm × 40 cm and water depth of 30 cm is: a) 8 N. b) 12 N. c) 720 N. d) 24 N. Using ${F = \rho g h A}$, the thrust is calculated as ${F = 720}$ N. 11 / 40 Category: JAMB Physics 2019 11. An object of mass 50g is suspended from a spring of force constant 0.5 N/m and set into SHM with displacement 0.3 m. The period is: a) 1.00 s. b) 1.99 s. c) 3.00 s. d) 2.50 s. Using ${T = 2 \pi \sqrt{\frac{m}{k}}}$, where ${m = 0.05}$ kg and ${k = 0.5}$ N/m, solving gives ${T \approx 1.99}$ s. 12 / 40 Category: JAMB Physics 2019 12. 21g of alcohol (density 0.7 g/cm${^3}$) is mixed with 10 g of water. The density of the mixture is: a) 780 g/cm${^3}$ b) 0.78 g/cm${^3}$ c) 30 g/cm${^3}$ d) 10 g/cm${^3}$ Density is calculated using ${\rho = \frac{\text{Total Mass}}{\text{Total Volume}}}$, yielding ${\rho = 0.78}$ g/cm${^3}$. 13 / 40 Category: JAMB Physics 2019 13. Two masses of 50g and 70g are suspended from opposite ends of a meter rule. The center of gravity of the system is: a) 50.0 cm. b) 52.3 cm. c) 70.2 cm. d) 80.4 cm. The center of gravity is calculated as the weighted average of distances, yielding 52.3 cm. 14 / 40 Category: JAMB Physics 2019 14. A transformer producing 10 V from 240 V supply has 60% efficiency. If secondary current is 15 A, primary current is: a) 15.0 A. b) 1.04 A. c) 16.04 A. d) 13.96 A. Using ${P_s = P_p \times \text{Efficiency}}$, solve for primary current: ${I_p = 1.04}$ A. 15 / 40 Category: JAMB Physics 2019 15. The acceleration due to gravity: a) Increases with altitude. b) Decreases with altitude. c) Increases with ${r^2}$. d) Not altitude dependent. Acceleration due to gravity decreases as altitude increases, because ${g \propto \frac{1}{r^2}}$. 16 / 40 Category: JAMB Physics 2019 16. A nail is pulled at an angle of 30° to the wall with tension 50 N. Effective pulling force is: a) 25 N. b) ${25\sqrt{3}}$ c) 50 N. d) ${50\sqrt{3}}$ The horizontal component of force is ${F_x = T \cos(30°) = 25}$ N. 17 / 40 Category: JAMB Physics 2019 17. Electromagnetic waves sensitive to temperature changes are: a) UV rays. b) Gamma rays. c) Infrared rays. d) X-rays. Infrared rays are sensitive to temperature changes and used in thermal imaging. 18 / 40 Category: JAMB Physics 2019 18. A spring-mass system has amplitude A, constant k, and mass m. Max potential energy is: a) kA. b) ${\frac{1}{2}kA^2}$ c) mkA. d) ${\frac{kA^2}{m}}$ Maximum potential energy is given by ${E_p = \frac{1}{2} k A^2}$. 19 / 40 Category: JAMB Physics 2019 19. A transformer connected to 240 V a.c has 500 turns in primary coil and 25 turns in secondary. Induced e.m.f is: a) 9.6 V. b) 12.0 V. c) 120.0 V. d) 52.1 V. Using ${\frac{V_s}{V_p} = \frac{N_s}{N_p}}$, solve for ${V_s \approx 12}$ V. 20 / 40 Category: JAMB Physics 2019 20. The fundamental frequency of a sonometer wire may be halved by: a) Reducing tension. b) Reducing temperature. c) Doubling length. d) Doubling mass. Doubling the wire length doubles the wavelength, halving frequency. 21 / 40 Category: JAMB Physics 2019 21. A car of mass 800 kg attains a speed of 25 m/s in 20 seconds. The power developed in the engine is: a) ${25 \times 10^4}$ W. b) ${50 \times 10^4}$ W. c) ${25 \times 10^6}$ W. d) ${50 \times 10^6}$ W. Power is given by ${P = \frac{\Delta KE}{\Delta t} = \frac{1}{2}mv^2/t}$. Calculation yields ${P = 25 \times 10^4}$ W. 22 / 40 Category: JAMB Physics 2019 22. When the brakes of a car are applied, the frictional force on the tires: a) Disadvantage (same direction). b) Disadvantage (opposite direction). c) Advantage (same direction). d) Advantage (opposite direction). The friction opposes motion, aiding in stopping the car, making it advantageous. 23 / 40 Category: JAMB Physics 2019 23. A solid weighs 10.0 N in air, 6.0 N in water, and 7.0 N in liquid X. The relative density of liquid X is: a) ${\frac{5}{3}}$ b) ${\frac{4}{3}}$ c) ${\frac{3}{4}}$ d) ${\frac{7}{10}}$ Relative density ${= \frac{W_{\text{apparent in X}}}{W_{\text{apparent in water}}} = \frac{3}{4}}$. 24 / 40 Category: JAMB Physics 2019 24. When the temperature of a liquid increases, its surface tension: a) Decreases. b) Increases. c) Remains constant. d) Increases then decreases. Surface tension decreases with increasing temperature because cohesive forces weaken. 25 / 40 Category: JAMB Physics 2019 25. A gas has initial volume ${V_0}$ and pressure ${P_0}$. Compressed to ${\frac{V_0}{5}}$, the pressure is: a) ${\frac{P_0}{5}}$ b) ${\frac{4P_0}{5}}$ c) ${P_0}$ d) ${5P_0}$ From Boyle’s law ${P_1V_1 = P_2V_2}$, solve for ${P_2 = 5P_0}$. 26 / 40 Category: JAMB Physics 2019 26. Waterfall is 420 m high; calculate the temperature difference if no heat is lost. a) 10°C b) 42°C c) 4.2°C d) 1°C Using ${\Delta T = \frac{mgh}{mc}}$, solve to find ${\Delta T = 1°C}$. 27 / 40 Category: JAMB Physics 2019 27. A body in neutral equilibrium is displaced slightly. It will: a) Rest in a new position. b) Return to original position. c) Remain in displaced position. d) Move further from original position. 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. A spring of length 5m extends 0.04m under load. Applied force 16N gives extension: a) 0.04m. b) 0.12m. c) 0.01m. d) 0.08m. Using Hooke’s law, ${\Delta L = \frac{F}{k}}$, solve for ${\Delta L = 0.08m}$. 29 / 40 Category: JAMB Physics 2019 29. Which of the following has negligible mass? a) Protons. b) Gamma rays. c) Beta particles. d) Alpha particles. Gamma rays are photons with negligible mass and high energy. 30 / 40 Category: JAMB Physics 2019 30. Energy loss due to eddy currents can be minimized by: a) High resistance wires. b) Insulated soft iron wires. c) Low resistance wires. d) Turns of wires. Eddy currents are minimized using laminated cores or soft insulated iron wires. 31 / 40 Category: JAMB Physics 2019 31. Upthrust on an object of volume 50 cm${^3}$ in liquid density ${10^3}$ kgm${^{-3}}$: a) 0.8N. b) 2.5N. c) 0.5N. d) 1.0N. Upthrust ${= V \times \rho \times g}$. Solving gives 0.5 N. 32 / 40 Category: JAMB Physics 2019 32. A white screen illuminated by red and green light appears as: a) Red. b) Purple. c) Yellow. d) Green. Red and green light combine to form yellow, which appears on the screen. 33 / 40 Category: JAMB Physics 2019 33. Electric field intensity between plates of 6.5 V and separation 35 cm: a) 18.57 NC${^{-1}}$ b) 53.06 NC${^{-1}}$ c) 2.28 NC${^{-1}}$ d) 0.80 NC${^{-1}}$ Field intensity ${= \frac{V}{d} = \frac{6.5}{0.35}}$. Solve for ${E = 18.57}$ NC${^{-1}}$. 34 / 40 Category: JAMB Physics 2019 34. Object distance reduced by 9.2 cm; find new distance from plane mirror: a) 17.50 cm. b) 15.50 cm. c) 18.50 cm. d) 16.50 cm. The total distance is halved. Calculation gives 15.50 cm. 35 / 40 Category: JAMB Physics 2019 35. Potential energy of 10 kg object at height 10 m above ground: a) 10,000 J. b) 5,000 J. c) 100 J. d) 1,000 J. Potential energy ${= mgh}$. Substitution gives 10,000 J. 36 / 40 Category: JAMB Physics 2019 36. Volume of gas changes from 10 cm${^3}$ at 400 cmHg to pressure 200 cmHg; find new volume: a) 30 cm${^3}$ b) 40 cm${^3}$ c) 50 cm${^3}$ d) 20 cm${^3}$ From Boyle’s law, ${P_1V_1 = P_2V_2}$. Solve for ${V_2 = 20}$ cm${^3}$. 37 / 40 Category: JAMB Physics 2019 37. Product PV of gas represents: a) Impulse. b) Power. c) Force. d) Work. Pressure × volume gives work, as it has the same unit (Joule). 38 / 40 Category: JAMB Physics 2019 38. Cost of running 7 × 40 W lamps and 5 × 80 W lamps for 12 hrs; energy costs ₦7.00/kWh: a) ₦80.00. b) ₦45.36. c) ₦65.00. d) ₦57.12. Total power = ${7 \times 40 + 5 \times 80}$. Calculate total cost as ${\frac{\text{Power} \times \text{time}}{1000} \times \text{cost per kWh}}$. Result is ₦57.12. 39 / 40 Category: JAMB Physics 2019 39. Velocity ratio of inclined plane is given by: a) ${\frac{1}{\sin \theta}}$ b) ${\sin \theta}$ c) ${\cos \theta}$ d) ${\tan \theta}$ The velocity ratio is ${\frac{1}{\sin \theta}}$. 40 / 40 Category: JAMB Physics 2019 40. An object is placed beyond the center of a concave mirror. The image forms: a) At infinity. b) At the center. c) At the focus. d) Between center and focus. 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
