WAEC Physics questions

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

1. Question 61· Elasticity· WAEC

   The energy stored in a spring of constant 400 N/m stretched by 0.05 m is

   • A1 J
   • B0.5 J
   • C20 J
   • D10 J

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2. Question 62· Elasticity· WAEC

   The SI unit of stress is the

   • Am
   • BN m
   • CN
   • DN m⁻²

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3. Question 63· Elasticity· WAEC

   Beyond the yield point, a stretched wire

   • Areturns to its original length
   • Bobeys Hooke's law
   • Cundergoes plastic deformation
   • Dhas no extension

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4. Question 64· Elasticity· WAEC

   A spring stretches by 2 cm under a load of 4 N. Find its extension under a load of 10 N, within the elastic limit.

   • A8 cm
   • B20 cm
   • C5 cm
   • D2.5 cm

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5. Question 65· Elasticity· WAEC

   Strain is defined as

   • Aoriginal length divided by extension
   • Bforce divided by area
   • Cforce divided by extension
   • Dextension divided by original length

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6. Question 66· Elasticity· WAEC

   A spring of force constant 200 N/m is stretched by 5 cm. What force is applied?

   • A40 N
   • B1000 N
   • C10 N
   • D4 N

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7. Question 67· Electric cells· WAEC

   A cell of e.m.f. 3 V and internal resistance 1 Ω is connected to a 5 Ω resistor. The current is

   • A0.75 A
   • B0.6 A
   • C3 A
   • D0.5 A

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8. Question 68· Electric cells· WAEC

   The e.m.f. of a cell is best measured when the cell is

   • Aconnected to a lamp
   • Bsupplying a large current
   • Cshort-circuited
   • Dsupplying no current

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9. Question 69· Electric cells· WAEC

   A battery of e.m.f. 12 V and internal resistance 2 Ω drives current through a 10 Ω lamp. Find the terminal p.d.

   • A10 V
   • B12 V
   • C2 V
   • D1.2 V

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10. Question 70· Electric cells· WAEC

    A cell of e.m.f. 9 V and internal resistance 1 Ω supplies a current of 2 A. The lost volts are

    • A7 V
    • B2 V
    • C9 V
    • D11 V

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11. Question 71· Electric cells· WAEC

    A lead-acid accumulator differs from a dry Leclanché cell in that it

    • Acan be recharged
    • Bcannot be recharged
    • Chas no electrolyte
    • Dgives no current

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12. Question 72· Electric cells· WAEC

    A new Leclanché cell is said to have a long shelf life. Which part of a simple voltaic cell, by contrast, is eaten away even when no current is drawn?

    • Athe copper plate
    • Bthe impure zinc plate
    • Cthe dilute acid
    • Dthe connecting wire

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13. Question 73· Electric cells· WAEC

    Local action in a simple cell can be reduced by

    • Ausing a stronger acid
    • Brubbing the zinc plate with mercury (amalgamation)
    • Cadding more copper
    • Dheating the cell

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14. Question 74· Electric cells· WAEC

    The positive pole of a Leclanché cell is the

    • Aammonium chloride paste
    • Bzinc case
    • Ccarbon rod
    • Dcopper wire

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15. Question 75· Electric cells· WAEC

    Two identical cells, each of e.m.f. 1.5 V, are connected in parallel. The combined e.m.f. is

    • A3.0 V
    • B1.5 V
    • C0.75 V
    • D2.25 V

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16. Question 76· Electrical energy and power· WAEC

    The fuse rating for a 920 W appliance on a 230 V supply should be about

    • A13 A
    • B1 A
    • C5 A
    • D30 A

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17. Question 77· Electrical energy and power· WAEC

    Find the resistance of a lamp rated 100 W, 240 V.

    • A2.4 Ω
    • B576 Ω
    • C24 000 Ω
    • D0.42 Ω

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18. Question 78· Electrical energy and power· WAEC

    A fuse protects a circuit by

    • Aincreasing the voltage
    • Bstoring extra current
    • Cmelting when the current is too large
    • Dearthing the appliance

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19. Question 79· Electrical energy and power· WAEC

    A 2 kW heater is used for 3 hours. The energy used is

    • A0.67 kWh
    • B1.5 kWh
    • C5 kWh
    • D6 kWh

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20. Question 80· Electrical energy and power· WAEC

    A kettle is rated 960 W, 240 V. Find its resistance.

    • A230,400 Ω
    • B4 Ω
    • C0.25 Ω
    • D60 Ω

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