NECTA-2024-PHYSICS1-F4

Objectives: Necta review 2024

Physics 1 – CSEE 2024 Questions

Physics 1 – CSEE 2024

National Examinations Council of Tanzania

Prepared by: Sir H. MWALA
Under Mwalarean at educenter.biasharabora.com

1. Multiple Choice Questions

  1. What does the warning sign of a flame symbol on a red diamond indicate about a substance?
  2. Which of the following is not a use of relative density in everyday life?
  3. Which of the following are considered fundamental forces?
  4. Why does an air bubble rise from the bottom of a pond to the surface?
  5. How much heat energy is lost by a 40g copper block cooling from 140°C to 40°C?
  6. In a flow experiment, cooking oil takes 3 minutes and honey 10 minutes to pour. What does this show about honey?
  7. A model car is released from a compressed spring and comes to rest. What are the energy transformations?
  8. Which of the given circuit figures shows current flow that retains a magnet’s magnetic field strength?
  9. Which graph represents uniform motion in a straight line?
  10. Why are windmills often built in coastal, mountain gap, or plain regions?

2. Matching – Concepts in Simple Machines

Match List A with List B:

List A
  1. The ratio of the distance moved by effort to that by the load
  2. The ratio of the load raised to the effort applied
  3. A wheel with a rope around its groove
  4. Work output divided by work input × 100%
  5. A rigid bar moving about a fixed point
  6. A machine used to pull heavy loads along a slope
List B

A. A simple pulley
B. Combination pulley
C. Efficiency
D. Lever
E. Mechanical advantage
F. Single fixed pulley
G. An inclined plane
H. Velocity ratio

3. Reflection and Lenses

(a) Two mirrors A and B are inclined at 70°. A ray hits mirror A parallel to it. What is the angle of reflection on mirror A?

(b) A projector forms a sharp image with magnification 7. Object-to-screen distance is 160 cm. Find the focal length.

4. Pressure and Moments

(a) Air pressure is 76 cm Hg at mountain base and 65 cm at top. Calculate the mountain height.

(b) Two boys carry a ladder weighing 800 N. Q is 2 m from the center of gravity, P is 3 m. Determine their load support with a sketch.

5. Impulse and Load

(a) A 3 kg hammer hits a nail at 5 m/s, driving it 1 cm into wood. What is the impulse on the nail?

(b) A bicycle wheel (radius 45 cm) and rear sprocket (4.5 cm) receives 160 N effort. If efficiency is 80%, find the maximum load.

6. Expansion and Heat Transfer

(a) Why does a solid expand when placed in hot water? Explain using kinetic theory.

(b) A 200 g metal at 100°C is placed in 50 g water at 20°C. Find the final temperature of water.

7. Vibrations and Nuclear Reactions

(a) A closed pipe (open at one end) has a fundamental frequency of 400 Hz. Draw its fundamental and first overtone mode.

(b) Uranium-238 decays to Lead-206. How many alpha and beta particles are emitted?

8. Volcanoes and Tides

(a) Describe the three types of volcanoes with one example for each.

(b) Explain the two main types of ocean tides.

9. Capacitors and Electricity

(a) Capacitors of 15 μF, 25 μF, and X in series give 7 μF total. What is the type of connection? Find X.

(b) In the given circuit, calculate current in each of three resistors.

(c) A bulb (0.25 kW), TV (0.5 kW), heater (3 kW), iron (2 kW) run from 6–11 pm. Cost per kWh is Tsh 80. Find total cost.

10. Rays and Rectifiers

(a) How do cathode rays differ from X-rays under magnetic/electric fields and with a paddle wheel?

(b) Distinguish between hard and soft X-rays with applications.

(c) Draw a simple rectifier circuit using diode, resistor, and step-down transformer. Indicate waveform types.

11. Sound and Security Alarm

(a) A man stands between two walls. Echoes are 0.4s apart. Find the distance between walls.

(b) Draw a labeled diagram of an induction coil. Give two applications.

(c) Given a relay circuit diagram for a security alarm:

  • Explain how the circuit works step-by-step.
  • Why is it considered “fail safe”?

End of Questions — Prepared by Sir H. Mwala under Mwalarean at educenter.biasharabora.com

Physics 1 – CSEE 2024 Questions and Answers

Physics 1 – CSEE 2024

National Examinations Council of Tanzania

1. Multiple Choice Questions

  1. What does the following warning sign mean in relation to the contents in the container?
    Answer: C - Flammable
    Reason: The flame symbol on a red diamond background indicates flammable material.
  2. The following are the uses of relative density in everyday life, except:
    Answer: C - Identification of germs
    Reason: Relative density is a physical property and has no role in identifying biological agents like germs.
  3. Which one represents the fundamental forces?
    Answer: C - Gravitational, and electromagnetic forces
    Reason: These are fundamental physical forces in nature.
  4. If a bubble of air is released at the bottom of a water pond, it will rise to the surface. Why?
    Answer: E - Upthrust is greater than the weight of the air bubble
  5. How much heat energy is given out by a copper block of 40 g mass cooling from 140°C to 40°C?
    Answer: E - 20800 J
  6. What distinguishes honey from cooking oil in a flow experiment?
    Answer: A - Honey has a higher viscosity than cooking oil
  7. Energy changes when a model car is released from a spring:
    Answer: D - Spring potential energy → Kinetic energy → Gravitational potential energy
  8. Which figure(s) allow a magnet to retain magnetic strength?
    Answer: D - Figure 1 and 3
  9. Which graph(s) represent motion at uniform velocity?
    Answer: D - 1 and 3
  10. Why are windmills constructed around coastal areas and hills?
    Answer: B - Because there are no obstructions and strong winds blow to rotate turbines

2. Matching - Simple Machines

  • (i) Velocity ratio → H
  • (ii) Mechanical advantage → E
  • (iii) Fixed pulley → F
  • (iv) Efficiency → C
  • (v) Lever → D
  • (vi) Inclined plane → G

3. Reflection and Lens Calculations

(a) Angle of reflection: 70°

(b) Focal length: 17.5 cm

4. Pressure and Moment

(a) Height of mountain: Approximately 1218 m

(b) Q supports: 480 N, P supports: 320 N

5. Impulse and Load

(a) Impulse on nail: 15 Ns

(b) Maximum load: 1280 N

6. Kinetic Theory and Calorimetry

(a) Solids expand due to increased vibration of particles.

(b) Final temperature: ~41.7°C

7. Waves and Nuclear Reactions

(a) Modes in closed pipe: Fundamental = ¼λ, First overtone = ¾λ

(b) 8 α-particles and 6 β-particles emitted

8. Volcanoes and Ocean Tides

(a) Active: Mount Etna, Dormant: Mt. Kilimanjaro, Extinct: Mt. Elgon

(b) Tides caused by moon’s gravitational pull: High tide and Low tide

9. Capacitors and Electricity

(a) Capacitors are in series; X ≈ 27.6 μF

(b) Currents: 1Ω → 4A, 6Ω → 1.33A, 3Ω → 2.67A

Voltages: 1Ω → 4V, 6Ω and 3Ω → 8V

(c) Cost = Tsh 2300

10. Rays and Circuits

(a) Cathode rays deflected; X-rays not. Cathode rays move paddle wheel.

(b) Hard X-rays penetrate deeper; soft X-rays safer for medical use

(c) Rectifier circuit includes diode, transformer, resistor

11. Sound and Electromagnetism

(a) Wall separation distance: 99 m

(b) Induction coil: contains primary, secondary coils and iron core

Applications: Ignition in engines, cathode-ray tubes

(c) Relay circuit: coil activates magnet, armature moves, bell rings when door opens

Fail-safe: Bell rings if wire breaks or door is forced

Reference Book: N/A

Author name: SIR H.A.Mwala Work email: biasharaboraofficials@gmail.com
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