JAMB and WAEC Physics questions

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

1. Question 41· Change of state· WAEC

   Evaporation differs from boiling in that evaporation

   • Aoccurs at all temperatures from the surface
   • Boccurs at a fixed temperature
   • Cproduces bubbles
   • Dneeds no heat

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2. Question 42· Change of state· JAMB

   How much heat is given out when 0.2 kg of steam at 100 °C condenses to water at 100 °C? (L = 2.26 × 10⁶ J/kg)

   • A4.52 × 10⁵ J
   • B2.26 × 10⁵ J
   • C1.13 × 10⁷ J
   • D4.52 × 10⁶ J

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3. Question 43· Change of state· JAMB

   Find the heat needed to melt 2 kg of ice at 0 °C. (Specific latent heat of fusion = 3.36 × 10⁵ J/kg)

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

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4. Question 44· Change of state· JAMB

   How much heat changes 0.1 kg of water at 100 °C into steam? [specific latent heat of vaporisation = 2.26 × 10⁶ J/kg]

   • A2.26 × 10⁷ J
   • B2.26 × 10⁵ J
   • C2.26 × 10⁴ J
   • D4.2 × 10⁴ J

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5. Question 45· Change of state· JAMB

   How much heat is needed to change 0.1 kg of water at 100 °C into steam at 100 °C? (Latent heat of vaporisation = 2.26 × 10⁶ J/kg)

   • A2.26 × 10⁶ J
   • B2.26 × 10⁵ J
   • C2.26 × 10⁴ J
   • D4.2 × 10⁴ J

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6. Question 46· Change of state· JAMB

   At the top of a high mountain, water boils at a temperature

   • Ahigher than 100 °C
   • Blower than 100 °C
   • Cof exactly 100 °C
   • Dof 0 °C

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7. Question 47· Conduction of electricity through liquids and gases· JAMB

   A fluorescent tube gives out light because of

   • Achemical reactions
   • Ba heated filament
   • Celectrical discharge through a gas at low pressure
   • Dnuclear decay

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8. Question 48· Conduction of electricity through liquids and gases· WAEC

   The mass of a substance liberated in electrolysis by one coulomb of charge is its

   • Avalency
   • Bmolar mass
   • Crelative atomic mass
   • Delectrochemical equivalent

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9. Question 49· Conduction of electricity through liquids and gases· WAEC

   Pure water is a poor conductor of electricity because it contains

   • Ano hydrogen
   • Bno molecules
   • Ctoo many electrons
   • Dvery few ions

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10. Question 50· Conduction of electricity through liquids and gases· JAMB

    Thermionic emission is the release of

    • Alight from a hot gas
    • Bprotons from a nucleus
    • Celectrons from a heated metal surface
    • Dions from a solution

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11. Question 51· Conduction of electricity through liquids and gases· JAMB

    In an electrolysis, doubling the current and keeping the time the same will make the mass deposited

    • Astay the same
    • Bhalve
    • Cdouble
    • Dbecome four times

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12. Question 52· Conduction of electricity through liquids and gases· JAMB

    A current of 2 A flows for 30 minutes through a copper sulphate solution. Find the mass of copper deposited. (Electrochemical equivalent of copper = 3.3 × 10⁻⁷ kg/C)

    • A1.98 × 10⁻⁵ kg
    • B1.19 × 10⁻³ kg
    • C3.3 × 10⁻⁷ kg
    • D2.38 × 10⁻³ kg

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13. Question 53· Conduction of electricity through liquids and gases· WAEC

    A fluorescent tube produces light by

    • Aheating a filament
    • Ban electric discharge through a gas at low pressure
    • Cburning a gas
    • Dchemical reaction in a cell

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14. Question 54· Conduction of electricity through liquids and gases· JAMB

    Faraday's first law of electrolysis states that the mass of a substance liberated is proportional to the

    • Aquantity of electricity passed
    • Bvoltage applied
    • Cvolume of the electrolyte
    • Dtemperature of the electrolyte

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15. Question 55· Conduction of electricity through liquids and gases· JAMB

    Cathode rays are

    • Astreams of neutrons
    • Bstreams of protons
    • Celectromagnetic waves
    • Dstreams of electrons

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16. Question 56· Conduction of electricity through liquids and gases· JAMB

    Gases conduct electricity most readily at

    • Ahigh pressure and high voltage
    • Bhigh pressure and low voltage
    • Clow pressure and high voltage
    • Datmospheric pressure and low voltage

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17. Question 57· Conduction of electricity through liquids and gases· JAMB

    In the electrolysis of copper(II) sulphate solution with copper electrodes,

    • Acopper dissolves from the anode and is deposited on the cathode
    • Boxygen is given off at the anode
    • Cthe solution turns colourless quickly
    • Dhydrogen is given off at the cathode

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18. Question 58· Conduction of electricity through liquids and gases· WAEC

    During the electrolysis of copper(II) sulphate solution with copper electrodes, the mass of the cathode

    • Aincreases
    • Bdecreases
    • Cstays the same
    • Dbecomes zero

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19. Question 59· Conduction of electricity through liquids and gases· JAMB

    An electrolyte conducts electricity by the movement of

    • Aprotons only
    • Belectrons only
    • Cneutrons
    • Dions

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20. Question 60· Conduction of electricity through liquids and gases· WAEC

    A current of 3 A flows for 10 minutes through an electrolyte. The electrochemical equivalent of the metal is 3 × 10⁻⁷ kg/C. Find the mass deposited.

    • A9 × 10⁻⁷ kg
    • B5.4 × 10⁻⁴ kg
    • C1.8 × 10⁻⁴ kg
    • D5.4 × 10⁻² kg

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