prelim

• What is the voltage of the mains supply to the toaster?

  230 V
• What is the power rating of the toaster's heating element?

  1.2 kW
• How much electrical energy does the heating element transfer each second?

  12000 J
• What is the appropriate fuse rating for the toaster's plug?

  13 A
• What is the charge passing through the heating element each second?

  230 C
• Which statements about the toaster are correct?


  • Statement I: Correct (12000 J per second)
  • Statement II: Correct (Fuse rated at 13 A)
  • Statement III: Incorrect (Charge is not 230 C)
• What is the resistance of the first resistor connected between X and Y?

  12 Ω
• What is the resistance of the second resistor connected between X and Y?

  6.0 Ω
• What is the resistance of the third resistor connected between X and Y?

  4.0 Ω
• What is being asked about the resistors connected between X and Y?

  The total resistance between X and Y
• What are the possible total resistance values given in the options?

  0.5 Ω, 2.0 Ω, 4.0 Ω, 6.0 Ω, 22 Ω
• If the resistors are in series, what is the total resistance?

  $12 +$$6 +$$4 =$$22 \, \Omega$
• If the resistors are in parallel, what is the formula for total resistance?

  $\frac{1}{R_{total}} =$$\frac{1}{R_1} +$$\frac{1}{R_2} +$$\frac{1}{R_3}$
• What is the total resistance if the resistors are in parallel?

  $\frac{1}{R_{total}} =$$\frac{1}{12} +$$\frac{1}{6} +$$\frac{1}{4}$
• What is the total resistance calculated from the parallel formula?

  $R_{total} =$$2 \, \Omega$
• Which option corresponds to the total resistance between X and Y?

  B 2.0 Ω
• What is the resistance of the wire?

  8.0 Ω
• What is the current in the wire?

  1.5 A
• How is power developed in the wire calculated?

  Power = Current^2 × Resistance
• What is the power developed in the wire with 8.0 Ω resistance and 1.5 A current?

  $Power =$$(1.5 \text{ A})^2 \times (8.0 \, \Omega) =$$18 \text{ W}$
• What is the correct answer for the power developed in the wire?

  C 18 W
• What is the formula for buoyancy force?

  F = pgl
• What does the variable 'p' represent in the buoyancy formula?

  Density of the fluid in kg m⁻³
• What does the variable 'g' represent in the buoyancy formula?

  Gravitational field strength in N kg⁻¹
• What does the variable 'l' represent in the buoyancy formula?

  Volume of the object in m³
• If an object experiences a buoyancy force of 360 N, what is the volume of the object in a fluid of density 1020 kg m⁻³?


  0.036 m³
• How do you calculate the volume of an object using the buoyancy force and fluid density?

  Volume = Buoyancy force / (Density * g)
• What is the density of the fluid in the given problem?

  1020 kg m⁻³
• What is the buoyancy force experienced by the object?

  360 N
• What are the answer choices for the volume of the object?

  A: 0.036 m³, B: 0.33 m³, C: 3.5 m³, D: 28 m³, E: 37000 m³