CBSE Class 10 Science Chapter 12 Magnetic Effects of Electric Current — 20 MCQs with Answers

A magnetic field is a region around a magnet or current-carrying conductor where a magnetic force can be detected. NCERT defines field lines as imaginary curves that show the direction a north pole would move. Questions here test the properties of field lines: they never intersect, emerge from the north pole and merge at the south pole, and their density indicates field strength. Understanding these basics is essential before tackling electromagnetic induction or motor principles.

The right-hand thumb rule gives the direction of the magnetic field around a straight current-carrying conductor. Point your thumb along the current; your curled fingers show the field's circular direction. This is a staple in CBSE Class 10 Science Chapter 12 MCQs. The rule extends to solenoids: grip the coil so fingers follow current loops; thumb points to the magnetic north pole. Mixing up thumb and fingers is a common mistake in exams — practice with actual diagrams.

Fleming's left-hand rule determines the direction of force (motion) when a current-carrying conductor is placed in a magnetic field. Stretch your left hand so the First finger points along the magnetic Field (N→S), seCond finger (middle) along Current, then the thuMb shows the direction of Motion (force). This principle underlies the electric motor. Board examiners love testing the hand used (left for motor, right for generator) and finger assignments. CBSE Class 10 Science chapter 12 quiz questions frequently include labelled diagrams where you identify the force direction.

Electromagnetic induction is the production of an induced current when a conductor moves relative to a magnetic field, or when the magnetic flux through a circuit changes. Michael Faraday discovered that the magnitude of induced EMF is proportional to the rate of change of flux. NCERT Class 10 Science MCQ on this topic test understanding of factors affecting induced current: speed of motion, number of turns in the coil, and strength of the magnet. Remember, no relative motion means zero induced current.

An AC generator (alternator) converts mechanical energy into electrical energy using electromagnetic induction. A coil rotates in a magnetic field; as flux through it changes, an alternating EMF is induced. Fleming's right-hand rule: First finger for Field, thuMb for Motion of the conductor, seCond finger (middle) for induced Current. The slip-ring and brush arrangement allows continuous current collection while the coil spins. Understanding the difference between AC generator (slip rings) and DC generator/motor (split-ring commutator) is crucial for CBSE Class 10 Science chapter 12 quiz questions.

While Chapter 12 focuses on magnetic effects, NCERT also touches on practical safety: fuses, MCBs (miniature circuit breakers) and earthing. A fuse is a thin wire that melts and breaks the circuit when current exceeds a safe limit. An MCB is a resettable switch that trips on overload. Earthing connects the metal body of an appliance to the ground, so any leakage current flows to earth instead of through a person. Board exams sometimes include a application-based MCQ linking circuit protection with magnetic overload (motor overheating). Important questions in Class 10 Science magnetic effects of electric current also test why an MCB is preferred over a fuse.

CBSE Class 10 Science Chapter 12 magnetic effects of electric current multiple choice questions trip students who memorise rules without understanding their physical basis. Mistake one: confusing left-hand and right-hand rules — remember left is for motor (force/motion from current), right is for generator (current from motion). Mistake two: thinking a stationary coil in a steady field will induce current — flux must change. Mistake three: mixing up solenoid polarity; always use right-hand thumb rule with fingers following current loops. Mistake four: not reading assertion-reason questions fully — both statements might be true but not causally linked. Reviewing these pitfalls raises your score by 2–3 marks.

At CBSETUTOR.ai, you get a 24×7 AI tutor that solves Chapter 12 MCQs via photo upload and explains each option's correctness in under 30 seconds. Stuck on why option B is wrong? Ask follow-up questions in chat. The platform covers every NCERT Class 10 Science chapter, offers unlimited practice sets and tracks your weak areas — electromagnetic induction, Fleming's rules, or circuit safety. Parents love the flat ₹999 per month pricing for Classes 6 to 12, with no hidden fees. Start your 3-day free trial today and watch your child's confidence soar before the boards. Real-time doubt clearing beats last-minute panic; one photo can save an hour of textbook hunting.

In the 2025 CBSE Class 10 Science paper, Section A has 16 MCQs (1 mark each) to be solved in roughly 20 minutes if you allocate time proportionally. That is 75 seconds per question. Start with questions you know cold — magnetic field line properties, right-hand thumb rule direction — to bank easy marks. Mark tricky assertion-reason or numerical MCQs for review. Eliminate two obviously wrong options first; if stuck between two, go with NCERT language (the answer that uses textbook terms like 'electromagnetic induction' rather than casual phrases). Never leave an MCQ blank; there is no negative marking. In the last two minutes, revisit marked questions and make an educated guess. This disciplined approach can secure 14–15 out of 16 in Section A.