WAEC Physics questions

379 questions with answers and explanations. Tap an option to check yourself.

1. Question 121· Equilibrium of forces· WAEC

   The principle of moments states that for a body in equilibrium

   • Athe body must be moving
   • Ball forces act downwards
   • Cthe weight is zero
   • Dthe sum of clockwise moments equals the sum of anticlockwise moments

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2. Question 122· Equilibrium of forces· WAEC

   A cone resting on its flat base is in

   • Aneutral equilibrium
   • Bunstable equilibrium
   • Cstable equilibrium
   • Dno equilibrium

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3. Question 123· Equilibrium of forces· WAEC

   A uniform plank resting on a support is in equilibrium. Which statement must be true?

   • AThe support must be at the centre of the plank
   • BThe plank must be horizontal
   • CThe clockwise moments about the support equal the anticlockwise moments
   • DThe weight of the plank is zero

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4. Question 124· Equilibrium of forces· WAEC

   Find the moment of a 15 N force acting perpendicularly 0.4 m from a pivot.

   • A0.6 N m
   • B37.5 N m
   • C15.4 N m
   • D6 N m

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5. Question 125· Equilibrium of forces· WAEC

   A ball resting on a level table is in

   • Astable equilibrium
   • Bneutral equilibrium
   • Cunstable equilibrium
   • Dno equilibrium

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6. Question 126· Equilibrium of forces· WAEC

   A uniform metre rule balances at its 50 cm mark. A 30 g mass hangs at the 20 cm mark. Where must a 20 g mass hang to restore balance?

   • A80 cm mark
   • B95 cm mark
   • C70 cm mark
   • D5 cm mark

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7. Question 127· Equilibrium of forces· WAEC

   A see-saw pivoted at its centre has a 400 N child 1.5 m from the pivot. How far on the other side must a 300 N child sit to balance?

   • A1.5 m
   • B2.0 m
   • C1.125 m
   • D2.5 m

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8. Question 128· Equilibrium of forces· WAEC

   A racing car is made with a low centre of gravity and wide wheel base to

   • Aincrease speed
   • Bincrease stability
   • Creduce friction
   • Dincrease weight

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9. Question 129· Equilibrium of forces· WAEC

   A cone resting on its tip is in

   • Astable equilibrium
   • Bunstable equilibrium
   • Cneutral equilibrium
   • Dno equilibrium

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10. Question 130· Friction· WAEC

    Friction is useful in

    • Aproducing unwanted heat
    • Bwearing out machine parts
    • Cwalking and braking
    • Dreducing efficiency

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11. Question 131· Friction· WAEC

    Which of these increases friction between two surfaces?

    • Aoiling the surfaces
    • Broughening the surfaces
    • Cusing ball bearings
    • Dstreamlining

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12. Question 132· Friction· WAEC

    A horizontal force of 80 N keeps a 20 kg box moving steadily along a floor. Find the coefficient of friction. (g = 10 m/s²)

    • A0.4
    • B4
    • C0.25
    • D2.5

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13. Question 133· Friction· WAEC

    Friction is useful because it

    • Awears out machine parts
    • Ballows the brakes of a car to work
    • Cproduces unwanted heat
    • Dwastes energy

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14. Question 134· Friction· WAEC

    Which of the following reduces friction between moving parts of a machine?

    • ALubrication
    • BRoughening the surfaces
    • CIncreasing the load
    • DUsing sand

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15. Question 135· Friction· WAEC

    Which of these reduces friction between moving parts?

    • Aremoving the ball bearings
    • Broughening the surfaces
    • Cincreasing the normal reaction
    • Dlubricating them with oil

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16. Question 136· Friction· WAEC

    The friction acting on a body sliding over a surface is usually

    • Azero
    • Bgreater than the limiting friction
    • Cequal to its weight
    • Dless than the limiting friction

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17. Question 137· Friction· WAEC

    A block of weight 50 N needs a horizontal force of 20 N to slide at constant speed. The coefficient of kinetic friction is

    • A2.5
    • B0.4
    • C0.2
    • D70

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18. Question 138· Friction· WAEC

    A horizontal force of 12 N just moves a block of weight 40 N on a level floor. Find the coefficient of static friction.

    • A28
    • B3.3
    • C0.48
    • D0.3

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19. Question 139· Gas laws· WAEC

    A gas occupies 200 cm³ at a pressure of 100 kPa. At constant temperature, what volume will it occupy at 400 kPa?

    • A400 cm³
    • B800 cm³
    • C100 cm³
    • D50 cm³

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20. Question 140· Gas laws· WAEC

    The pressure law states that at constant volume the pressure of a fixed mass of gas is

    • Ainversely proportional to temperature
    • Bdirectly proportional to its absolute temperature
    • Cconstant
    • Dproportional to volume

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