JAMB Physics questions

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

1. Question 21· 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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2. Question 22· 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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3. Question 23· 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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   Explanation and discussion

4. Question 24· 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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   Explanation and discussion

5. Question 25· 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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6. Question 26· 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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7. Question 27· 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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8. Question 28· 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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9. Question 29· 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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10. Question 30· 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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11. Question 31· 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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12. Question 32· 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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13. Question 33· 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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14. Question 34· 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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15. Question 35· Conduction of electricity through liquids and gases· JAMB

    In electroplating a spoon with silver, the spoon is made the

    • Aanode
    • Bcathode
    • Celectrolyte
    • Dbattery

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16. Question 36· Conduction of electricity through liquids and gases· JAMB

    In a cathode-ray tube, the electrons are produced by

    • Athermionic emission from a heated cathode
    • Bradioactive decay
    • Cfriction
    • Dchemical action

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17. Question 37· Conduction of electricity through liquids and gases· JAMB

    Cathode rays are streams of

    • Aelectrons
    • Bprotons
    • Celectromagnetic waves
    • Dneutrons

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18. Question 38· Current electricity· JAMB

    

    In the circuit shown, the battery has negligible internal resistance. Find the current drawn from the battery.

    • A1 A
    • B1.2 A
    • C6 A
    • D3 A

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19. Question 39· Current electricity· JAMB

    

    In the circuit shown, the cell has negligible internal resistance. Find the effective resistance of the three resistors.

    • A0.67 Ω
    • B15 Ω
    • C2.0 Ω
    • D1.5 Ω

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20. Question 40· Current electricity· JAMB

    

    In the circuit shown, the cell has negligible internal resistance. Find the current through the 3 Ω resistor.

    • A0.5 A
    • B1.0 A
    • C2.0 A
    • D3.0 A

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    Explanation and discussion