JAMB and WAEC Physics questions

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

1. Question 21· Capacitors· WAEC

   A capacitor stores 60 μC when charged to 12 V. Find its capacitance.

   • A72 μF
   • B720 μF
   • C0.2 μF
   • D5 μF

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2. Question 22· Capacitors· JAMB

   Placing a dielectric between the plates of a capacitor increases its capacitance because the dielectric

   • Areduces the electric field between the plates for the same charge
   • Bconducts charge between the plates
   • Cincreases the distance between the plates
   • Dreduces the area of the plates

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3. Question 23· Capacitors· WAEC

   A capacitor stores a charge of 0.002 C at 50 V. Find its capacitance.

   • A2.5 × 10⁴ F
   • B0.1 F
   • C4 × 10⁻⁵ F
   • D4 × 10⁻³ F

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4. Question 24· Change of state· JAMB

   Adding salt to ice

   • Alowers its melting point
   • Braises its melting point
   • Chas no effect on its melting point
   • Dturns it into steam

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5. Question 25· Change of state· JAMB

   Increasing the pressure on water

   • Aremoves its latent heat
   • Braises its boiling point
   • Cdoubles its volume
   • Dchanges its colour

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6. Question 26· Change of state· WAEC

   The flat part of a cooling curve shows that the substance is

   • Againing heat
   • Bcooling fastest
   • Cat room temperature
   • Dchanging state

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7. Question 27· Change of state· WAEC

   While water is boiling its temperature stays constant because the heat supplied

   • Ais used to overcome the forces between molecules
   • Bescapes to the surroundings
   • Craises the kinetic energy of the molecules
   • Dis changed into light

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8. Question 28· Change of state· WAEC

   How much heat is needed to melt 0.2 kg of ice at 0 °C? [specific latent heat of fusion = 3.36 × 10⁵ J/kg]

   • A6.72 × 10⁴ J
   • B3.36 × 10⁴ J
   • C1.68 × 10⁶ J
   • D6.72 × 10⁵ J

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9. Question 29· Change of state· JAMB

   Wet clothes dry faster on a windy day because wind

   • Aadds water
   • Braises the boiling point
   • Cremoves the vapour and speeds up evaporation
   • Dcools the sun

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10. Question 30· Change of state· WAEC

    Boiling differs from evaporation because boiling

    • Atakes place at all temperatures
    • Btakes place at a definite temperature throughout the liquid
    • Coccurs only at the surface
    • Dproduces no vapour

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11. Question 31· Change of state· JAMB

    Evaporation causes cooling because

    • Aheat flows into the liquid
    • Bthe liquid absorbs cold from the air
    • Cthe liquid's mass increases
    • Dthe faster molecules escape, lowering the average kinetic energy of those left

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12. Question 32· Change of state· WAEC

    Food cooks faster in a pressure cooker because

    • Athe pressure lowers the boiling point
    • Bthe higher pressure raises the boiling point of water
    • Csteam escapes quickly
    • Dless heat is needed to melt it

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13. Question 33· Change of state· WAEC

    Evaporation differs from boiling because evaporation

    • Aoccurs throughout the liquid
    • Btakes place only at 100 °C
    • Ctakes place at all temperatures from the surface of the liquid
    • Dneeds no heat

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14. Question 34· Change of state· JAMB

    While a pure liquid is boiling, its temperature

    • Arises and falls
    • Brises steadily
    • Cfalls steadily
    • Dremains constant

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15. Question 35· Change of state· WAEC

    Heat required to melt 0.5 kg of ice at 0 °C (latent heat 3.4 × 10⁵ J/kg) is

    • A6.8 × 10⁵ J
    • B1.7 × 10⁵ J
    • C3.4 × 10⁵ J
    • D3.4 × 10⁴ J

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16. Question 36· Change of state· WAEC

    Find the heat needed to change 2 kg of water at 100 °C to steam. (Specific latent heat = 2.26 × 10⁶ J/kg)

    • A4.52 × 10⁶ J
    • B2.26 × 10⁶ J
    • C1.13 × 10⁶ J
    • D9.04 × 10⁶ J

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17. Question 37· Change of state· JAMB

    A pressure cooker cooks food faster because

    • Asteam is a poor conductor
    • Bit lowers the boiling point of water
    • Cit uses less water
    • Dthe increased pressure raises the boiling point of water

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18. Question 38· Change of state· WAEC

    The heat absorbed when a solid changes to a liquid without a change in temperature is called

    • Alatent heat of vaporisation
    • Blatent heat of fusion
    • Cspecific heat capacity
    • Dheat of combustion

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19. Question 39· Change of state· WAEC

    The change of a substance directly from solid to vapour is called

    • Acondensation
    • Bevaporation
    • Csublimation
    • Dmelting

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20. Question 40· Change of state· JAMB

    The specific latent heat of fusion of a substance is the heat needed to

    • Araise 1 kg of it by 1 K
    • Bchange 1 kg of it from solid to liquid without a change of temperature
    • Cboil 1 kg of it
    • Dmelt any amount of it

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