Diese Aufgaben gibt es in ihrer Originalsprache.

1. Thema: Units

   1. What is the SI unit of force?

   AJouleBNewtonCWattDPascal
   Lösung

   B. Newton

   • Force is measured in newtons (N).
   • 1 N is the force that gives a 1 kg mass an acceleration of 1 m/s².

2. Thema: Motion

   2. A car starts from rest and reaches 20 m/s in 5 s with uniform acceleration. Find its acceleration.

   A2 m/s²B4 m/s²C25 m/s²D100 m/s²
   Lösung

   B. 4 m/s²

   • Acceleration = change in velocity ÷ time.
   • (20 − 0) ÷ 5 = 4 m/s².

3. Thema: Scalars and vectors

   3. Which of the following is a vector quantity?

   AMassBSpeedCVelocityDEnergy
   Lösung

   C. Velocity

   • A vector has both magnitude and direction.
   • Velocity is speed in a given direction, so it is a vector. Mass, speed and energy are scalars.

4. Thema: Current electricity

   4. A conductor carries a current of 3 A when the potential difference across it is 12 V. Find its resistance.

   A0.25 ΩB4 ΩC15 ΩD36 Ω
   Lösung

   B. 4 Ω

   • Ohm's law: R = V ÷ I.
   • R = 12 ÷ 3 = 4 Ω.

5. Thema: Current electricity

   5. Two 6 Ω resistors are connected in parallel. What is their combined resistance?

   A3 ΩB6 ΩC12 ΩD36 Ω
   Lösung

   A. 3 Ω

   • For two resistors in parallel: 1/R = 1/6 + 1/6 = 2/6.
   • R = 6 ÷ 2 = 3 Ω.

6. Thema: Waves

   6. A wave has a frequency of 50 Hz and a wavelength of 2 m. Find its speed.

   A25 m/sB48 m/sC52 m/sD100 m/s
   Lösung

   D. 100 m/s

   • Wave speed v = fλ.
   • v = 50 × 2 = 100 m/s.

7. Thema: Work and energy

   7. Calculate the work done in lifting a 10 kg load through a height of 2 m. (g = 10 m/s²)

   A20 JB50 JC200 JD2000 J
   Lösung

   C. 200 J

   • Work done = force × distance, and the force needed is the weight mg.
   • W = 10 × 10 × 2 = 200 J.

8. Thema: Heat

   8. How much heat is needed to raise the temperature of 2 kg of water by 10 °C? (c = 4200 J/kg °C)

   A8,400 JB21,000 JC42,000 JD84,000 J
   Lösung

   D. 84,000 J

   • Heat Q = mcΔθ.
   • Q = 2 × 4200 × 10 = 84,000 J.

9. Thema: Electromagnetic waves

   9. Which electromagnetic wave has the shortest wavelength?

   ARadio wavesBVisible lightCX-raysDGamma rays
   Lösung

   D. Gamma rays

   • Gamma rays have the highest frequency in the electromagnetic spectrum.
   • Highest frequency means shortest wavelength.

10. Thema: Momentum

    10. Find the momentum of a 5 kg object moving at 4 m/s.

    A1.25 kg m/sB9 kg m/sC20 kg m/sD40 kg m/s
    Lösung

    C. 20 kg m/s

    • Momentum p = mv.
    • p = 5 × 4 = 20 kg m/s.