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PRIME MINISTER’S OFFICE-REGIONALADMINISTRATION AND LOCAL GOVERNMENT

PHYSICS DEPARTMENT

CURRENT ELECTRICITY-TEST TWO

TIME 2:30HRS

YEAR 2026

INSTRUCTIONS

ANSWER ALL QUESTIONS

1. (a) (i) Why is the voltmeter made of high internal resistance?

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(ii) With the aid of diagram, explain how the voltmeter is connected in a circuit

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(b) Two wires of 10Ω and 5Ω are in parallel, and the arrangement is in series with a 20Ω

wire. If the current in the 5Ω wire is 2A, calculate the current in the 10Ω wire and the

p.d V across the whole circuit.

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2. (a) Why it is preferable to connect bulbs in parallel than in series

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(b) Study the circuit below and answer the next questions

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Calculate the current when

i

The switch 퐾1 is closed while 퐾2 is open

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ii

Both switches 퐾1 and 퐾2 are closed

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iii

Switch 퐾1is open and 퐾2is closed

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3. (a)Explain why resistance cannot be accurately measured using just a voltmeter and

ammeter.

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(b) Calculate the current across each resistor in the circuit diagram below.

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4. (a) Why is an ammeter constructed with a low resistance?

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(b) In the figure below, the labels A, B, C and D are identical electric bulbs connected in a

circuit. Explain what will happen to the bulbs A, B and D when bulb C blows off and the

key K is closed.

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5. (a) The figure below shows an electric circuit. Carefully study it and calculate the value of

the current x and r

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(b) In the figure below, lamp 퐿3 shines brighter but lamp 퐿4 is dimmer when switch 푺ퟐis

closed. Give reason for this.

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6. Study carefully the diagram below and answer the next questions

a)

If the switch 푺ퟏ is closed

i. Describe the brightness of the lamps 퐿1 and 퐿2

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ii.

What will 퐴2 if 퐴1 reads 1.0A?

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b)

If the switch 푺ퟏ is opened

i. Describe the brightness of the lamp 퐿1and 퐿2

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ii.

What happens to the readings of the ammeters?

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7. If the resistances of the ammeters in the figure below are ignored, explain each of the

following observations:

i.

when switch S is closed, the current through A1 is less than that through A2

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ii.

when switch S is opened, the current through A2 falls

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iii.

When switch S is opened, the current through each ammeter is the same.

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8. (a) State ohm’s law

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(b) In an experiment to verify ohm’s law, the following circuit diagram was provided to

students. Give the names of components U, W, X and Y

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(c) A potential difference of 10V is applied across parallel resistors of 3Ω and 6Ω

i.

Draw a circuit diagram including a cell and switch.

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ii.

Calculate the combined resistance

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iii.

Calculate the current flowing through a circuit

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9. (a) Draw a series circuit containing a battery, switch, lamp, a variable resistor and an

ammeter connected so that it can be used to measure the current in the lamp

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(b) Draw a circuit with a battery and switch in series, two lamps in parallel and a voltmeter

connected so that it can be used to measure the voltage across one of the lamps

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(c)How does ohm’s law explain the fact that the resistance of a conductor depends on the

area of cross – section of the conductor?

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10. (a) Why does a bird safely porch on a high potential electric wire?

(b) Distinguish between.

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a. Parallel circuit and series circuit.

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b. Ammeter and voltmeter

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c. Resistance and equivalent resistance

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(c) State the factors that affect the resistance of a conductor.

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