← Back to papers
CSEE 🇹🇿 NECTA ✓ Official NECTA answers

Physics · Paper 1 · 2022

24 questions

💰 Sit full exam 200 TZS

3-hour timed simulation · auto-graded · counts toward ranking

Pay & start exam →
Questions (24)

Section A

1. 1 mark

Which set best represents fundamental quantities with their SI units?

A. Length (km), mass (kg), time (s), temperature (C), amount of substance (mol) and electric current (A).
B. Length (m), mass (kg), force (N), temperature (K), time (s), amount of substance (mol) and energy (U).
C. Length (m), mass (kg), time (s), electric current (), temperature ( C) and amount of substance (mol).
D. Length (m), mass (kg), time (), temperature (K), electric current (A) and luminous intensity (Cd).
E. Length (km), mass (g), time ($), temperature (K), electric current (A) and amount of substance (mol).
2. 1 mark

Which one of the following conditions must be satisfied for a body to float?

A. Apparent weight is equal to the difference between real weight of the body and its upthrust.
B. Upthrust equals to the weight of the fluid displaced.
C. Real weight of the body equals to its upthrust.
D. Apparent weight is equal to the product of real weight of a body and its upthrust
E. Density of a body is equal to the density of surrounding fluid.

Section B

3. 10 marks

(a) A concave mirror is used to form an image of a pin object. By using a well labelled diagram; show how you can obtain an upright and enlarged image. 4 mk Diagram for part a
(b) With the aid of diagrams, describe three ways in which a human eye can be compared to photographic camera. 6 mk

Upgrade to see model answers.

4. 9 marks

Carefully study the Figure 2 and then answer the question that follows: Atmospheric pressure is $1.0 imes 10^5 Pa$ and density of mercury is 13.6 g/cm$^3$.

(a) Find the pressure $P$ in the gas. 5 mk
(b) Name any other three forces acting on the gas. 4 mk
(c) Why can a ship not overturn when hit by a strong wave on one side? 4 mk

Upgrade to see model answers.

5. 10 marks

Figure 3 shows a car moving to a farm. Manure Car Trailer String O

(a) Identify four pairs of action/reaction forces taking place and describe their effects. 4 mk
(b) A pulley system with efficiency of 75% is made up of four pulleys. Sketch a well labelled diagram of this machine and then determine the effort required to raise two bags of maize each weighing 100 kg. 6 mk Diagram for part b

Upgrade to see model answers.

6. 6 marks

Figure 4 shows a circuit diagram for controlling the temperature of a sitting room. Copper strip Switch Contact Brass Iron Bimetallic strip Heater element

(none) Figure 4 shows a circuit diagram for controlling the temperature of a sitting room. Describe how the circuit controls the temperature when the switch is closed. 6 mk
(a) Describe how the circuit controls the temperature when the switch is closed. 6 mk

Upgrade to see model answers.

7. 4 marks

The half-life of a radioactive substance is 138 days. A sample of the substance has 1.0 x 10undecayed atoms at the beginning. How many undecayed atoms will be left after 690 days?

(a) how long does it take for the water to boil when the two coils are joined in series 4 mk
(b) The half-life of a radioactive substance is 138 days. A sample of the substance has 1.0 x 10^8 undecayed atoms at the beginning. How many undecayed atoms will be left after 690 days? 4 mk

Upgrade to see model answers.

8. 5 marks

Analyze five effects of volcanoes eruption on the Earth's Surracethe elto A urnlng rork produces resonances in a tube at 40 cm and 85 cm respectively.

Diagram for question 8
(a) Analyze five effects of volcanoes eruption on the Earth's Surface. 5 mk
(b) A tuning fork produces resonances in a tube at 40 cm and 85 cm respectively. Calculate the wavelength of the tuning fork. 5 mk

Upgrade to see model answers.

Section C

9. 6 marks

When a potential difference of 60 V is applied across a primary circuit of a transformer, a current of 3.7 A flows. Find the potential difference across the secondary circuit if there is a current of 0.15 A flowing in it. Take the efficiency of the transformer to be 95 %.

(a) A stretched taut string of length 40 cm and mass 2 x 10^-3 kg is pulled with a tension of 100 N. Determine the frequency of the first and second harmonics when it is plucked at its middle. 6 mk
(b) When a potential difference of 60 V is applied across a primary circuit of a transformer, a current of 3.7 A flows. Find the potential difference across the secondary circuit if there is a current of 0.15 A flowing in it. Take the efficiency of the transformer to be 95 %. 6 mk

Upgrade to see model answers.

10. 3 marks

With the aid of a common-emitter amplifier circuit, explain why n-p-n transistor is named SO.

(a) Explain four factors that affect the resistance of a conductor. 4 mk
(b) The parallel combination of 2 Ω and 5 Ω resistors are connected across the external resistor of 3 Ω through the supply of 4 V. Draw the circuit diagram and find the current flowing through a 5 Ω resistor. 5 mk
(c) With the aid of a common-emitter amplifier circuit, explain why n-p-n transistor is named so. 3 mk

Upgrade to see model answers.

11. 6 marks

How does sound from the disco hall transmitted into your room? Briefly explain.

(a) How does sound from the disco hall transmitted into your room? Briefly explain. 6 mk
(b) How are the microwaves used in cooking? 2 mk
(c) How is the destructive interference used in noise reduction system? Briefly describe. 4 mk

Upgrade to see model answers.

💡 Unlock all answers & explanations
Premium · 3000 TZS/mo