✅ Q1.
Which of the following correctly describes the magnetic field near a long straight wire?
- (d) 🎯 The field consists of concentric circles centred on the wire.
✅ Q2.
At the time of short circuit, the current in the circuit:
- (c) 🎯 increases heavily.
✅ Q3.
State whether the following statements are true or false.
- (a) The field at the centre of a long circular coil carrying current will be parallel straight lines. → ✅ True
- (b) A wire with a green insulation is usually the live wire of an electric supply. → ❌ False (Green is used for earth wire, not live)
✅ Q4.
List two methods of producing magnetic fields:
🎯
- Passing an electric current through a straight conductor.
- Using a permanent magnet.
✅ Q5.
When is the force experienced by a current–carrying conductor placed in a magnetic field largest?
🎯 When the conductor is placed perpendicular to the magnetic field.
✅ Q6.
Imagine you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally from back wall to front wall, is deflected by a strong magnetic field to your right side. What is the direction of magnetic field?
🎯 Using Fleming’s left-hand rule, the magnetic field is directed vertically downward.
✅ Q7.
State the rules:
- (i) 🎯 Magnetic field around a straight conductor → Right-Hand Thumb Rule: If the thumb of the right hand points in the direction of current, the curled fingers show the direction of magnetic field.
- (ii) 🎯 Force on a current-carrying conductor → Fleming’s Left-Hand Rule: Thumb = force, First finger = field, Second finger = current.
- (iii) 🎯 Current induced in a coil → Fleming’s Right-Hand Rule: Thumb = motion, First finger = field, Second finger = induced current.
✅ Q8.
When does an electric short circuit occur?
🎯 When the live wire and neutral wire come into direct contact, causing a sudden, large current due to very low resistance.
✅ Q9.
What is the function of an earth wire? Why is it necessary to earth metallic appliances?
🎯 The earth wire provides a low-resistance path for current to the ground in case of leakage of current.
🎯 It is necessary to earth metallic appliances to prevent electric shock and protect the user.