Introduction

PAREEKSHA.IN

Volume 3: General Science

Electricity and Magnetism

Comprehensive Study Notes for SSC and Railway (RRB) Competitive Examinations

Introduction

Electricity and Magnetism form one of the most scoring and consistently examined areas of General Science in SSC (CGL, CHSL, MTS, GD Constable) and Railway (RRB NTPC, Group D, ALP) examinations. Unlike some topics in biology or chemistry that demand rote memorisation of long lists, this chapter rewards conceptual understanding: once a student grasps how charge, current, and magnetic fields behave, most exam questions become straightforward applications of a handful of laws and formulas. This chapter is organised into two broad parts. The first part, Electricity, builds up from the basic idea of electric charge to circuits, household wiring, and the heating and chemical effects of current. The second part, Magnetism, covers magnets, the Earth's magnetic field, and the deeply important link between electricity and magnetism known as electromagnetism — the principle behind motors, generators, and transformers. Throughout, particular attention is paid to the kind of one-line factual questions ('who discovered X', 'what is the SI unit of Y') that recur year after year in these examinations, as well as to the numerical-formula-based questions that test whether a candidate can actually apply Ohm's law or the power formula under exam pressure.

PART A: ELECTRICITY