10 questions · Form 2 Science Bab 7: Electricity and Magnetism
When rubbing an ebonite rod with woolen cloth, the ebonite rod becomes negatively charged. What happened during rubbing?
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. When rubbing an ebonite rod with woolen cloth, the ebonite rod becomes negatively charged. What happened during rubbing?
Answer: B
Friction causes electrons to move from the woolen cloth onto the ebonite rod, giving the ebonite rod an excess negative charge.
2. Which rule is applied to determine the direction of the magnetic field around a straight current-carrying wire?
Answer: B
The Right-Hand Grip Rule determines magnetic field direction: pointing the thumb in current flow direction causes fingers to curl in magnetic field direction.
3. In a series circuit containing three identical 3 Ω resistors, what is the total effective resistance?
Answer: D
In a series circuit, total resistance R_total = R1 + R2 + R3 = 3 Ω + 3 Ω + 3 Ω = 9 Ω.
4. What electrostatic hazard is prevented by attaching heavy metallic earthing chains to fuel tanker trucks?
Answer: B
Friction between fuel and pipes/air builds static electricity; grounding chains continuously discharge charges safely to the ground to prevent explosive sparks.
5. What is the primary unit used to measure electric current?
Answer: C
Electric current is measured in Amperes (A) using an ammeter.
6. How does the total effective resistance of a parallel circuit change as more parallel resistor branches are added?
Answer: B
Adding extra parallel paths gives current more alternative routes to flow, lowering overall effective resistance.
7. An electric circuit powered by a 12 V battery draws a current of 2 A. According to Ohm's Law (V = IR), what is the total resistance of the circuit?
Answer: A
Resistance R = VI = 12 V2 A = 6 Ω.
8. How should an Ammeter and a Voltmeter be connected to measure electric current and potential difference across a bulb, respectively?
Answer: B
An ammeter must be placed in series to measure total current passing through, while a voltmeter must be placed in parallel across the component to measure potential difference.
9. An uncharged object becomes negatively charged when it undergoes which process?
Answer: B
Gaining additional electrons creates an excess of negative charge over positive protons, giving the object a net negative charge.
10. In a series circuit, how does potential difference (V) distribute across two lightbulbs with resistances of 2 Ω and 4 Ω?
Answer: B
In series circuits, total voltage divides proportionally across resistors (V = IR); higher resistance receives a larger share of voltage.