WAEC Physics questions

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

1. Question 281· Quantity of heat· WAEC

   A 500 W heater is switched on for 2 minutes. How much heat does it produce?

   • A60 000 J
   • B1000 J
   • C250 J
   • D30 000 J

   Show answer

   Explanation and discussion

2. Question 282· Quantity of heat· WAEC

   How much heat is needed to raise 2 kg of water from 20 °C to 70 °C? [specific heat capacity of water = 4200 J/kg K]

   • A8400 J
   • B420 000 J
   • C210 000 J
   • D588 000 J

   Show answer

   Explanation and discussion

3. Question 283· Quantity of heat· WAEC

   Water is used as a coolant in car radiators because it has a

   • Alow boiling point
   • Bhigh specific heat capacity
   • Clow density
   • Dhigh expansivity

   Show answer

   Explanation and discussion

4. Question 284· Quantity of heat· WAEC

   The quantity of heat needed to raise the temperature of a whole body by 1 K is its

   • Aspecific heat capacity
   • Bheat capacity
   • Clatent heat
   • Dthermal conductivity

   Show answer

   Explanation and discussion

5. Question 285· Quantity of heat· WAEC

   200 g of water at 80 °C is mixed with 300 g of water at 30 °C. Find the final temperature if no heat is lost.

   • A60 °C
   • B55 °C
   • C50 °C
   • D45 °C

   Show answer

   Explanation and discussion

6. Question 286· Quantity of heat· WAEC

   Find the heat capacity of a 0.5 kg block whose specific heat capacity is 900 J/kg K.

   • A450 J/K
   • B1800 J/K
   • C900 J/K
   • D0.00056 J/K

   Show answer

   Explanation and discussion

7. Question 287· Quantity of heat· WAEC

   How much heat is needed to raise the temperature of 2 kg of water by 10 °C? (specific heat capacity of water = 4,200 J/kg K)

   • A42,000 J
   • B8,400 J
   • C84,000 J
   • D21,000 J

   Show answer

   Explanation and discussion

8. Question 288· Quantity of heat· WAEC

   Find the heat needed to raise the temperature of 0.5 kg of copper by 40 °C. (c = 400 J/kg K)

   • A8,000 J
   • B800 J
   • C20,000 J
   • D80,000 J

   Show answer

   Explanation and discussion

9. Question 289· Scalars and vectors· WAEC

   Which pair consists of a scalar and a vector respectively?

   • Aforce and momentum
   • Bdisplacement and velocity
   • Cmass and time
   • Dspeed and acceleration

   Show answer

   Explanation and discussion

10. Question 290· Scalars and vectors· WAEC

    Which of these quantities has both size and direction?

    • Atime
    • Bmass
    • Cweight
    • Dwork

    Show answer

    Explanation and discussion

11. Question 291· Scalars and vectors· WAEC

    A force of 20 N acts at 60° to the horizontal. What is its horizontal component?

    • A17.3 N
    • B10 N
    • C20 N
    • D11.5 N

    Show answer

    Explanation and discussion

12. Question 292· Scalars and vectors· WAEC

    Forces of 6 N and 8 N act on a body at right angles to each other. Find their resultant.

    • A14 N
    • B10 N
    • C2 N
    • D48 N

    Show answer

    Explanation and discussion

13. Question 293· Scalars and vectors· WAEC

    A boat heads north at 4 m/s across a river flowing east at 3 m/s. Its resultant speed is

    • A5 m/s
    • B7 m/s
    • C1 m/s
    • D12 m/s

    Show answer

    Explanation and discussion

14. Question 294· Scalars and vectors· WAEC

    Which of the following pairs consists only of scalar quantities?

    • AMass and energy
    • BForce and speed
    • CVelocity and time
    • DWeight and length

    Show answer

    Explanation and discussion

15. Question 295· Scalars and vectors· WAEC

    Which of these quantities is a vector?

    • Amass
    • Bspeed
    • Cdisplacement
    • Denergy

    Show answer

    Explanation and discussion

16. Question 296· Scalars and vectors· WAEC

    A force of 50 N acts at 60° to the horizontal. Find its vertical component.

    • A25 N
    • B43.3 N
    • C50 N
    • D86.6 N

    Show answer

    Explanation and discussion

17. Question 297· Scalars and vectors· WAEC

    Two forces of 3 N and 4 N act at right angles on a body. The magnitude of their resultant is

    • A7 N
    • B1 N
    • C12 N
    • D5 N

    Show answer

    Explanation and discussion

18. Question 298· Scalars and vectors· WAEC

    Two forces of 6 N and 8 N act at right angles. The magnitude of their resultant is

    • A2 N
    • B14 N
    • C10 N
    • D48 N

    Show answer

    Explanation and discussion

19. Question 299· Scalars and vectors· WAEC

    Forces of 7 N and 3 N act on a body in the same direction. Find their resultant.

    • A7.6 N
    • B4 N
    • C21 N
    • D10 N

    Show answer

    Explanation and discussion

20. Question 300· Simple a.c. circuits· WAEC

    The reactance of a capacitor decreases when the frequency of the supply

    • Astays the same
    • Bdecreases
    • Cincreases
    • Dbecomes zero

    Show answer

    Explanation and discussion