2021 – JAMB PHYSICS PAST QUESTIONS & ANSWERS CBT PRACTICE You can also check in for latest; 9JA Music Gospel Music Foreign Music 3 12345678910111213141516171819202122232425262728293031323334353637383940 2021 - JAMB Physics Past Questions & Answers Cbt Practice 1 / 40 1. I. A liquid boils when its saturated vapor pressure is equal to the external pressure II. Dissolved substances in pure water lead to an increase in the boiling point. III. When the external pressure is increased, the boiling point increases. IV. Dissolved substances in pure water decreases the boiling point Which of the above combinations are peculiarities of the boiling point of a liquid? a) I, II, III, and IV b) I, II and III only c) II, III, and IV d) I, II, and IV 2 / 40 2. The lowest note emitted by a stretched string has a frequency of 40Hz. How many overtones are there between 40Hz and 180Hz? a) 4 b) 3 c) 1 d) 2 3 / 40 3. In a series R-L-C circuit at resonance, the voltages across the resistor and the inductors are 30V and 40V respectively. What is the voltage across the capacitor? a) 70V b) 30V c) 50V d) 40V 4 / 40 4. A man will exert the greatest pressure when he? a) stands on both feet b) stands on the toes of one foot c) lies on his belly d) lies flat on his back 5 / 40 5. A man stands 4m in front of a plane mirror. If the mirror is moved 1m towards the man, the distance between him and his new image is? a) 6m b) 3m c) 5m d) 10m 6 / 40 6. Particles of mass 10−2kg is fixed to the tip of a fan blade which rotates with angular velocity of 100rad−1. If the radius of the blade is 0.2m, the centripetal force is? a) 2N b) 20N c) 400N d) 200N 7 / 40 7. A given mass of gas has a pressure of 80 Nm¯² at a temperature of 47 C. If the temperature is reduced to 27 C with volume remaining constant, the new pressure is? a) 85.3 Nm¯² b) 80.0 Nm¯² c) 75.0 Nm¯² d) 46.0 Nm¯² 8 / 40 8. 0.5kg of water at 10ºC is completely converted to ice at 0ºC by extracting (88000) of heat from it. If the specific heat capacity of water is 4200jkg1 Cº. Calculate the specific latent heat of fusion of ice. a) 84.0kjkg¯¹ b) 134.0kjkg¯¹ c) 9.0kjkg¯¹ d) 168.0kjkg¯¹ 9 / 40 9. When the temperature of a liquid increases, its surface tension a) remains constant b) decreases c) increases d) increases then decreases 10 / 40 10. A source of sound produces waves in air of wavelength 1.65m. If the speed of sound in air is 330ms¯¹, the period of vibration in air is? a) 200 b) 0.02 c) 0.005 d) 0.5 11 / 40 11. If the stress on a wire is 10⁷NM¯² and the wire is stretched from its original length of 10.00m to 10.05m. The young's modulus of the wire is? a) 5.0 x 10¯⁴Nm¯² b) 5.0 x 10¯⁵Nm¯² c) 2.0 x 10¯⁸Nm¯² d) 2.0 x 10⁹Nm¯² 12 / 40 12. A boy standing some distance from the foot of a tall cliff claps his hands and hears an echo 0.5s later. If the speed of sound is 340ms¯¹, how far is he from the cliff? a) 34m b) 85m c) 680m d) 170m 13 / 40 13. A 2H inductor has negligible resistance and is connected to a 50/π Hz A.C supply. The reactance of the inductor is? a) 25/πΩ b) 50Ω c) 100/π d) 200Ω 14 / 40 14. A ball of mass 0.5kg moving at 10ms¯¹ collides with another ball of equal mass at rest. If the two balls move off together after the impact, calculate their common velocity. a) 0.5ms¯¹ b) 5.5ms¯¹ c) 0.2ms¯¹ d) 5.0ms¯¹ 15 / 40 15. The velocities of light in air and glass are 3.0 x 10⁸ms¯¹ and 2.0 x 10⁸ms¯¹ respectively. If the angle of refraction is 30º, the sine of the angle of incidence is? a) 0.33 b) 0.67 c) 0.75 d) 0.50 16 / 40 16. A gas at a volume of V0 in a container at pressure p0 is compressed to one-fifth of its volume. What will be its pressure if the magnitude of its original temperature T is constant? a) 4p0/5 b) po/5 c) 5po d) po 17 / 40 17. A solid weighs 10.00N in air, 6N when forcefully immersed in water, and 7.0N when fully immersed in a liquid, X. Calculate the relative density of the liquid X. a) 7/10 b) 5/3 c) 4/3 d) 3/4 18 / 40 18. Calculate the heat energy required to vaporize 50g of water initially at 80ºC if the specific heat capacity of water is 4.23jg¯¹k¯¹ (specific latent heat of vaporization of water is 2260jg a) 23200J b) 130000J c) 530000J d) 17200J 19 / 40 19. The motion of a body is simple harmonic if the? a) acceleration is constant and directed towards a fixed point b) path of motion is a straight line c) acceleration is proportional to the square of the distance from a fixed point d) acceleration is always directed towards a fixed point 20 / 40 20. Which of the following is not correct about the molecules of a substance in a gaseous state? They a) have different speeds b) The collision between the gases is perfectly inelastic c) are in a constant state of motion d) have a temperature which is measured by the average kinetic energy 21 / 40 21. A lead bullet of mass 0.05kg is fired with a velocity of 200ms¯¹ into a block of mass 0.95kg. Given that the lead block can move freely, the final kinetic energy after impact is? a) 200J b) 150J c) 50J d) 100J 22 / 40 22. Which of the following is not a vector quantity? a) momentum b) force c) temperature d) displacement 23 / 40 23. A piece of substance of specific heat capacity 450Jkg¯¹k¹ falls through a vertical distance of 20m from rest. Calculate the rise in temperature of the substance on hitting the ground when all its energies are converted into heat. [g = 10ms¯²] a) 4/9 ºC b) 2/9 ºC c) 9/4 ºC d) 9/2 ºC 24 / 40 24. An astronomical telescope is said to be in normal adjustment when the? a) final image is at the near point of eye b) focal length of an object lens is longer than that of eye piece c) eye is accommodated d) final image is at infinity 25 / 40 25. Two bodies have masses in the ratio3:1. They experience forces which impart to them, acceleration in the ratio 2:9 respectively. Find the ratio of forces the masses experienced a) 1:4 b) 2:5 c) 2:1 d) 2:3 26 / 40 26. If a sound wave goes from a cold air region to a hot air region, its wavelength will...? a) decrease b) remain constant c) decrease then increase d) increase 27 / 40 27. If the fraction of the atoms of radioactive material left after 120 years is 1/64, what is the half-life of the material? a) 10 years b) 20 years c) 2 years d) 24 years 28 / 40 28. Calculate the mass of ice that would melt when 2kg of copper is quickly transferred from boiling water to a block of ice without heat loss (specific heat capacity of copper = 400Jkg¹k¯¹, latent heat of fusion of ice = 3.3 x 10⁵Jkg¯¹) a) 8/33kg b) 3.3/80kg c) 80/33kg d) 3.3/8kg 29 / 40 29. The equation of a wave traveling along the positive x-direction is given by; y = 0.25 x 10¯³ sin (500t - 0.025x). Determine the angular velocity of the wave motion. a) 2.50 x 10³rads¯¹ b) 0.25 x 10¯³rads¯¹ c) 5.00 x 10²rads¯¹ d) 0.25 x 10¯¹rads¯¹ 30 / 40 30. A car of mass 800kg attains a speed of 25m/s in 20secs. The power developed in the engine is? a) 1.25 x 10⁶W b) 2.50 x 10⁶W c) 1.25 x 10⁴W d) 2.50x 10⁴W 31 / 40 31. Which of the following physical quantities units are derived? I. Area II. Thrust III. Pressure IV. Mass a) I, II, and IV only b) I and IV only c) i, II, and III only d) I, II, III and IV 32 / 40 32. The inner diameter of a test tube can be measured accurately using a? a) meter rule b) pair of vernier calipers c) pair of dividers d) micrometer screw gauge 33 / 40 33. The slope of the straight line displacement-time graph indicates? a) uniform velocity b) uniform acceleration c) uniform speed d) distance traveled 34 / 40 34. The inside portion of part of a hollow metal sphere of diameter 20cm is polished. The portion will therefore form a? a) convex mirror of focal length 5cm b) concave mirror of focal length 5cm c) convex mirror of focal length 10cm d) concave mirror of focal length 10cm 35 / 40 35. A ball of mass 0.1kg is thrown vertically upwards with a speed of 10ms¯¹ from the top of a tower 10m high. Neglecting air resistance, its total energy just before hitting the ground is? (Take g = 10ms¯²) a) 10J b) 5J c) 15J d) 20J 36 / 40 36. A certain radioactive source emits radiation that was found to be deflected by both magnetic and electric fields. The radiation is? a) x-rays b) ultra-violet rays c) gamma rays d) beta rays 37 / 40 37. The temperature gradient across a copper rod of thickness 0.02m, maintained at two temperature junctions of 20º and 80ºC respectively is? a) 3.0 x 10⁴km¯¹ b) 3.0 x 10³km¯¹ c) 5.0 x 10³km¯¹ d) 3.0 x 10²km¯¹ 38 / 40 38. If the frequency of an emitted x-ray is 1.6 x 10¹⁶Hz, the accelerating potential is? [e = 1.6 x 10¯¹⁹J, h = 6.63 x 10¯³⁴Js] a) 6.6V b) 663.0V c) 66.3V d) 6630.0V 39 / 40 39. When the breaks in a car are applied, the frictional force on the tyres is...? a) a disadvantage because it is in the opposite direction of the motion of the car b) an advantage because it is in the direction of the motion of the car c) a disadvantage because it is in the direction of the motion of the car d) an advantage because it is in the opposite direction of the motion of the car 40 / 40 40. Which of the following instruments may be used to measure relative humidity? a) Hygrometer b) Manometer c) Hypsometer d) Hydrometer Your score is The average score is 38% Restart Cbt Please click the stars to rate the quiz Send feedback
