2021 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 2021 JAMB PHYSICS PAST QUESTIONS AND ANSWERS 1 / 40 Category: JAMB Physics 2021 1. $$\text{Purpose of the vacuum in a thermos flask is to reduce heat loss by:}$$ a) $$\text{Convection.}$$ b) $$\text{Radiation.}$$ c) $$\text{Conduction.}$$ d) $$\text{Evaporation.}$$ $$\text{Vacuum prevents heat transfer via convection by eliminating air molecules.}$$ 2 / 40 Category: JAMB Physics 2021 2. $$\text{A body that emits light by itself is called:}$$ a) $$\text{Luminous body.}$$ b) $$\text{Non-luminous body.}$$ c) $$\text{Opaque body.}$$ d) $$\text{Transparent body.}$$ $$\text{Luminous bodies emit light independently without external illumination.}$$ 3 / 40 Category: JAMB Physics 2021 3. $$\text{Frictional force acting on } 20 \text{ kg mass with } \mu = 0.5 \text{ on horizontal surface:}$$ a) $$\text{80 N.}$$ b) $$\text{120 N.}$$ c) $$\text{100 N.}$$ d) $$\text{60 N.}$$ $$\text{Force } = \mu mg = 0.5 \times 20 \times 10 = 100 \text{ N.}$$ 4 / 40 Category: JAMB Physics 2021 4. $$\text{Velocity for placing a satellite in orbit around Earth with radius } 6.4 \times 10^6 \text{ m:}$$ a) $$\text{11.3 ms}^{-1}. $$ b) $$\text{10.2 ms}^{-1}. $$ c) $$\text{12.5 ms}^{-1}. $$ d) $$\text{15.0 ms}^{-1}. $$ $$\text{Orbital velocity } v = \sqrt{gR}. \text{ Solve for } v = 11.3 \text{ ms}^{-1}. $$ 5 / 40 Category: JAMB Physics 2021 5. $$\text{Force on an electron with charge } 1.6 \times 10^{-19} \text{ C moving at right angles in } B = 2.0 \times 10^{-4} \text{ T and } v = 1.5 \times 10^3 \text{ ms}^{-1}:$$ a) $$\text{3.2 } \times \text{ 10}^{-5} \text{ N.}$$ b) $$\text{6.4 } \times \text{ 10}^{-5} \text{ N.}$$ c) $$\text{2.4 } \times \text{ 10}^{-5} \text{ N.}$$ d) $$\text{4.8 } \times \text{ 10}^{-5} \text{ N.}$$ $$\text{Force } F = qvB. \text{ Substitution gives } F = 4.8 \times 10^{-5} \text{ N.}$$ 6 / 40 Category: JAMB Physics 2021 6. $$\text{The two processes essential in an air conditioning system are:}$$ a) $$\text{Evaporation and condensation.}$$ b) $$\text{Evaporation and melting.}$$ c) $$\text{Melting and freezing.}$$ d) $$\text{Freezing and condensation.}$$ $$\text{Air conditioning involves evaporation to absorb heat and condensation to release it, controlling temperature.}$$ 7 / 40 Category: JAMB Physics 2021 7. $$\text{Pressure at 200m swimming pool depth with } g = 10 \text{ ms}^{-2}, \rho = 10^3 \text{ kgm}^{-3}, \text{ and atmospheric pressure } = 1.3 \times 10^6 \text{ Nm}^{-2}:$$ a) $$\text{2.5 } \times \text{ 10}^{6} \text{ Nm}^{-2}. $$ b) $$\text{2.8 } \times \text{ 10}^{6} \text{ Nm}^{-2}. $$ c) $$\text{3.0 } \times \text{ 10}^{6} \text{ Nm}^{-2}. $$ d) $$\text{3.3 } \times \text{ 10}^{6} \text{ Nm}^{-2}. $$ $$\text{Pressure } P = \rho gh + P_\text{atm}. \text{ Solve for } P = 3.3 \times 10^6 \text{ Nm}^{-2}. $$ 8 / 40 Category: JAMB Physics 2021 8. $$\text{Spring constant when a force of } 10 \text{ N produces an extension of } 0.05 \text{ m:}$$ a) $$\text{100 Nm}^{-1}. $$ b) $$\text{150 Nm}^{-1}. $$ c) $$\text{200 Nm}^{-1}. $$ d) $$\text{250 Nm}^{-1}. $$ $$\text{Hooke’s law } F = kx. \text{ Solve for } k = \frac{F}{x} = 200 \text{ Nm}^{-1}. $$ 9 / 40 Category: JAMB Physics 2021 9. $$\text{Heat released when } 0.1 \text{ kg of steam condenses to water at } 100^{\circ}\text{C. Specific latent heat of vaporization is } 2.2 \times 10^6 \text{ Jkg}^{-1}:$$ a) $$\text{2.0 } \times \text{ 10}^{5} \text{ J.}$$ b) $$\text{1.8 } \times \text{ 10}^{5} \text{ J.}$$ c) $$\text{2.4 } \times \text{ 10}^{5} \text{ J.}$$ d) $$\text{2.2 } \times \text{ 10}^{5} \text{ J.}$$ $$\text{Heat } Q = mL. \text{ Substitution gives } Q = 0.1 \times 2.2 \times 10^6 = 2.2 \times 10^5 \text{ J.}$$ 10 / 40 Category: JAMB Physics 2021 10. $$\text{Cost of using a } 200 \text{ W electric iron for 5 hours at } \text{₦5.00 per kWh:}$$ a) $$\text{₦5.00.}$$ b) $$\text{₦10.00.}$$ c) $$\text{₦15.00.}$$ d) $$\text{₦20.00.}$$ $$\text{Energy consumed } = \frac{200}{1000} \times 5 = 1 \text{ kWh. Cost } = 1 \times 5 = \text{₦5.00.}$$ 11 / 40 Category: JAMB Physics 2021 11. $$\text{Radiation with the highest penetrating power:}$$ a) $$\text{Gamma rays.}$$ b) $$\text{Beta rays.}$$ c) $$\text{Alpha rays.}$$ d) $$\text{X-rays.}$$ $$\text{Gamma rays have the highest energy and penetration among electromagnetic radiation.}$$ 12 / 40 Category: JAMB Physics 2021 12. $$\text{Power of a convex lens with focal length } 20 \text{ cm:}$$ a) $$\text{4 D.}$$ b) $$\text{3 D.}$$ c) $$\text{2 D.}$$ d) $$\text{5 D.}$$ $$\text{Power } P = \frac{100}{f}. \text{ Solve for } P = \frac{100}{20} = 5 \text{ D.}$$ 13 / 40 Category: JAMB Physics 2021 13. $$\text{Power of a lift lifting } 1000 \text{ kg lift with } 650 \text{ kg people } 40 \text{ m in } 50 \text{ seconds:}$$ a) $$\text{132,000 W.}$$ b) $$\text{150,000 W.}$$ c) $$\text{140,000 W.}$$ d) $$\text{120,000 W.}$$ $$\text{Power } P = \frac{(m_1 + m_2)gh}{t}. \text{ Substitution gives } P = 132,000 \text{ W.}$$ 14 / 40 Category: JAMB Physics 2021 14. $$\text{Wavelength of air column in closed pipe resonating at } 0.425 \text{ m:}$$ a) $$\text{1.60 m.}$$ b) $$\text{1.70 m.}$$ c) $$\text{1.80 m.}$$ d) $$\text{1.90 m.}$$ $$\text{Wavelength } \lambda = 4l. \text{ Solve for } \lambda = 4 \times 0.425 = 1.70 \text{ m.}$$ 15 / 40 Category: JAMB Physics 2021 15. $$\text{Principle underlying a beam balance:}$$ a) $$\text{Conservation of energy.}$$ b) $$\text{Principle of inertia.}$$ c) $$\text{Law of motion.}$$ d) $$\text{Principle of moments.}$$ $$\text{Beam balance operates on the principle of moments, ensuring equilibrium between forces.}$$ 16 / 40 Category: JAMB Physics 2021 16. $$\text{Placement of an object in front of a concave mirror to form a magnified, upright, and virtual image:}$$ a) $$\text{Between the mirror and the focus.}$$ b) $$\text{At the center of curvature.}$$ c) $$\text{Beyond the center of curvature.}$$ d) $$\text{At the focus.}$$ $$\text{The object must be placed between the pole and the focus of the mirror.}$$ 17 / 40 Category: JAMB Physics 2021 17. $$\text{Example of a secondary cell:}$$ a) $$\text{Voltaic cell.}$$ b) $$\text{Dry cell.}$$ c) $$\text{Leclanché cell.}$$ d) $$\text{Thermocouple.}$$ $$\text{A secondary cell is rechargeable; an example is a voltaic cell.}$$ 18 / 40 Category: JAMB Physics 2021 18. $$\text{Component of the visible spectrum with the longest wavelength when white light is dispersed:}$$ a) $$\text{Red.}$$ b) $$\text{Green.}$$ c) $$\text{Violet.}$$ d) $$\text{Blue.}$$ $$\text{Red light has the longest wavelength among the visible spectrum.}$$ 19 / 40 Category: JAMB Physics 2021 19. $$\text{Condition for resonance in an alternating current circuit:}$$ a) $$\text{X_L > X_C.}$$ b) $$\text{X_L < X_C.}$$ c) $$\text{X_L = R.}$$ d) $$\text{X_L = X_C.}$$ $$\text{In resonance, the inductive reactance } X_L \text{ equals the capacitive reactance } X_C. $$ 20 / 40 Category: JAMB Physics 2021 20. $$\text{Shortest distance for a rescue boat to reach a stranded boat after traveling due east and 60° northeast:}$$ a) $$\text{67.66 m.}$$ b) $$\text{60.00 m.}$$ c) $$\text{70.00 m.}$$ d) $$\text{75.00 m.}$$ $$\text{Using the cosine rule, solve for the shortest distance as } 67.66 \text{ m.}$$ 21 / 40 Category: JAMB Physics 2021 21. $$\text{Definition of velocity ratio of a machine:}$$ a) $$\text{I, II, and IV.}$$ b) $$\text{I, II, and III.}$$ c) $$\text{II, III, and IV.}$$ d) $$\text{I and IV only.}$$ $$\text{The velocity ratio is defined as the ratio of the distance moved by the effort to the distance moved by the load.}$$ 22 / 40 Category: JAMB Physics 2021 22. $$\text{Relative density of a stone weighing } w_1 \text{ in air and } w_2 \text{ in water:}$$ a) $$\text{\frac{w_1}{w_2}.}$$ b) $$\text{\frac{w_2}{w_1}.}$$ c) $$\text{\frac{w_1 – w_2}{w_1}.}$$ d) $$\text{\frac{w_1}{w_1 – w_2}.}$$ $$\text{Relative density is calculated using the formula } \frac{w_1}{w_1 – w_2}. $$ 23 / 40 Category: JAMB Physics 2021 23. $$\text{Thickness of water when pin displacement viewed above is } 3 \text{ cm:}$$ a) $$\text{4 cm.}$$ b) $$\text{3 cm.}$$ c) $$\text{5 cm.}$$ d) $$\text{2 cm.}$$ $$\text{The formula for displacement helps find the actual thickness } h. \text{ Solve for } h = 4 \text{ cm.}$$ 24 / 40 Category: JAMB Physics 2021 24. $$\text{Voltmeter reading when the circuit key is closed:}$$ a) $$\text{Electromotive force.}$$ b) $$\text{Terminal voltage.}$$ c) $$\text{No reading.}$$ d) $$\text{Short-circuit voltage.}$$ $$\text{The voltmeter measures terminal voltage when current flows in the circuit.}$$ 25 / 40 Category: JAMB Physics 2021 25. $$\text{Minimum distance for an echo when sound speed in air is } 340 \text{ m/s:}$$ a) $$\text{160 m.}$$ b) $$\text{150 m.}$$ c) $$\text{180 m.}$$ d) $$\text{170 m.}$$ $$\text{For an echo, minimum distance } d = \frac{vt}{2} \text{ gives } d = 170 \text{ m.}$$ 26 / 40 Category: JAMB Physics 2021 26. $$\text{Isotope decay producing } ^{111}_{48}Y:$$ a) $$\text{Beta emission.}$$ b) $$\text{Alpha emission.}$$ c) $$\text{Gamma decay.}$$ d) $$\text{Photon emission.}$$ $$\text{The correct decay process yields the isotope } ^{111}_{48}Y. $$ 27 / 40 Category: JAMB Physics 2021 27. $$\text{Definition of temperature } -273 \degree C:$$ a) $$\text{Boiling point.}$$ b) $$\text{Melting point.}$$ c) $$\text{Sublimation point.}$$ d) $$\text{Absolute zero of temperature.}$$ $$\text{This temperature is known as the absolute zero of temperature.}$$ 28 / 40 Category: JAMB Physics 2021 28. $$\text{Moment of force } 40 \text{ N about the point O:}$$ a) $$\text{60 Nm.}$$ b) $$\text{80 Nm.}$$ c) $$\text{120 Nm.}$$ d) $$\text{140 Nm.}$$ $$\text{The moment of force is calculated using } \text{Moment} = F \times d. \text{ Here, } \text{Moment} = 40 \times 3 = 120 \text{ Nm.}$$ 29 / 40 Category: JAMB Physics 2021 29. $$\text{Magnetic element not determining Earth’s magnetic field:}$$ a) $$\text{Magnetic declination.}$$ b) $$\text{Magnetic inclination.}$$ c) $$\text{Electric induction.}$$ d) $$\text{Horizontal component.}$$ $$\text{The Earth’s magnetic field is determined by magnetic inclination, declination, and horizontal component but not electric induction.}$$ 30 / 40 Category: JAMB Physics 2021 30. $$\text{Equivalent capacitance of the given circuit:}$$ a) $$\text{2 F.}$$ b) $$\text{4 F.}$$ c) $$\text{3 F.}$$ d) $$\text{1 F.}$$ $$\text{For capacitors in series, the equivalent capacitance is } \frac{1}{C_{\text{eq}}} = \frac{1}{C_1} + \frac{1}{C_2}. \text{ Solve to get } 2 \text{ F.}$$ 31 / 40 Category: JAMB Physics 2021 31. $$\text{Electric intensity experienced by a } 60 \text{ C charge under } 12 \text{ N force:}$$ a) $$\text{2.0 N/C.}$$ b) $$\text{3.0 N/C.}$$ c) $$\text{1.5 N/C.}$$ d) $$\text{0.2 N/C.}$$ $$\text{Electric field intensity is calculated as } E = \frac{F}{q}. \text{ Here, } E = \frac{12}{60} = 0.2 \text{ N/C.}$$ 32 / 40 Category: JAMB Physics 2021 32. $$\text{Major carriers in a p-type semiconductor material:}$$ a) $$\text{Holes.}$$ b) $$\text{Electrons.}$$ c) $$\text{Protons.}$$ d) $$\text{Neutrons.}$$ $$\text{Holes are the majority charge carriers in p-type semiconductors due to the doping material used.}$$ 33 / 40 Category: JAMB Physics 2021 33. $$\text{Coefficient of superficial expansion of a material given its dimensions and temperature change:}$$ a) $$\text{2.2 \times 10^{-6} K^{-1}.}$$ b) $$\text{3.3 \times 10^{-6} K^{-1}.}$$ c) $$\text{4.0 \times 10^{-6} K^{-1}.}$$ d) $$\text{4.4 \times 10^{-6} K^{-1}.}$$ $$\text{Using the formula for expansion, } \text{coefficient } = \frac{\Delta L}{L \Delta T}, \text{ solve to get } 4.4 \times 10^{-6} \text{ K}^{-1}. $$ 34 / 40 Category: JAMB Physics 2021 34. $$\text{Process involved in the absorption of ink by blotting paper:}$$ a) $$\text{Capillary action.}$$ b) $$\text{Diffusion.}$$ c) $$\text{Osmosis.}$$ d) $$\text{Absorption.}$$ $$\text{Capillary action allows the ink to rise through the porous structure of the blotting paper.}$$ 35 / 40 Category: JAMB Physics 2021 35. $$\text{Substance with the largest heat capacity:}$$ a) $$\text{10 kJ of water.}$$ b) $$\text{1 kg of iron.}$$ c) $$\text{2 kJ of mercury.}$$ d) $$\text{1 kg of copper.}$$ $$\text{The substance with the largest heat capacity absorbs the most heat for the smallest temperature change.}$$ 36 / 40 Category: JAMB Physics 2021 36. $$\text{Resulting motion of a hunter’s spear at } 45^{\circ}:$$ a) $$\text{Zero range.}$$ b) $$\text{Short range.}$$ c) $$\text{Maximum range.}$$ d) $$\text{Unpredictable.}$$ $$\text{At } 45^{\circ}, \text{the projectile achieves maximum range because this angle optimizes horizontal and vertical components of motion.}$$ 37 / 40 Category: JAMB Physics 2021 37. $$\text{Component NOT part of a D.C. generator:}$$ a) $$\text{Split rings.}$$ b) $$\text{Commutator.}$$ c) $$\text{Brushes.}$$ d) $$\text{Slip rings.}$$ $$\text{Slip rings are components of an A.C. generator, while split rings are used in a D.C. generator.}$$ 38 / 40 Category: JAMB Physics 2021 38. $$\text{Thermometric property NOT indicated:}$$ a) $$\text{Change in resistance.}$$ b) $$\text{Change in volume.}$$ c) $$\text{Change in mass.}$$ d) $$\text{Change in pressure.}$$ $$\text{Mass is not a thermometric property, as it doesn’t change with temperature like volume, resistance, or pressure.}$$ 39 / 40 Category: JAMB Physics 2021 39. $$\text{Frequency of wave in ripple tank: } 60 \text{ waves in } 30 \text{ seconds:}$$ a) $$\text{2 Hz.}$$ b) $$\text{4 Hz.}$$ c) $$\text{1 Hz.}$$ d) $$\text{3 Hz.}$$ $$\text{Frequency } f = \frac{\text{Number of waves}}{\text{Time}} = \frac{60}{30} = 2 \text{ Hz.}$$ 40 / 40 Category: JAMB Physics 2021 40. $$\text{Mass of copper deposited with } 1.5 \text{ A current in } 900 \text{ s:}$$ a) $$\text{3.0 \times 10^{-4} kg.}$$ b) $$\text{4.0 \times 10^{-4} kg.}$$ c) $$\text{5.0 \times 10^{-4} kg.}$$ d) $$\text{4.5 \times 10^{-4} kg.}$$ $$\text{Mass deposited } m = zIt, \text{ where } z = 3.3 \times 10^{-2}, I = 1.5 \text{ A, } t = 900 \text{ s. Calculate } m = 3.3 \times 10^{-2} \times 1.5 \times 900 = 4.5 \times 10^{-4} \text{ kg.}$$ Your score is The average score is 0% LinkedIn Facebook Twitter VKontakte 0% Restart quiz Anonymous feedback Send feedback
