In-text Questions — Current and Charge — Electricity

1. 11 markNCERT Cl-10 Science, In-text Qs after §11.1, Q1

   What does an electric circuit mean?

   Hint. Think about what has to be true of the path for a bulb to actually light up.

   Step 1 — Recall what makes current flow at all. A torch bulb glows only when its switch is on, closing the path between the cell and the bulb.

   Step 2 — State the definition. Since current only flows through an unbroken path, a continuous and closed path of electric current is called an electric circuit.

   ✦ Answer: An electric circuit is a continuous and closed path along which an electric current flows.

   Where students slip. Describing a circuit as just 'the wires and components' without the closed-path requirement — an open (broken) arrangement of the same components isn't a working circuit at all.

2. 21 markNCERT Cl-10 Science, In-text Qs after §11.1, Q2

   Define the unit of current.

   Hint. The ampere is defined directly from the coulomb and the second.

   Step 1 — Recall the relationship between current, charge and time. Current I = Q/t.

   Step 2 — Apply it to define the unit. Since one ampere is the current when one coulomb of charge flows per second, 1 A = 1 C/1 s.

   ✦ Answer: One ampere is the current resulting from one coulomb of charge flowing per second (1 A = 1 C/s).

   Where students slip. Defining the ampere in terms of voltage or resistance — it's defined purely from charge and time, independent of those other quantities.

3. 32 marksNCERT Cl-10 Science, In-text Qs after §11.1, Q3

   Calculate the number of electrons constituting one coulomb of charge.

   Hint. Divide the total charge by the charge on a single electron.

   Step 1 — Recall the charge on one electron. e = 1.6 × 10⁻¹⁹ C.

   Step 2 — Divide to find the number of electrons. n = Q/e = 1/(1.6 × 10⁻¹⁹) = 6.25 × 10¹⁸, since dividing the total charge by one electron's charge gives the count of electrons.

   ✦ Answer: 6.25 × 10¹⁸ electrons make up one coulomb of charge.

   Where students slip. Multiplying instead of dividing (Q × e) — the number of electrons is the total charge divided by the charge of one electron, since dividing tells you how many individual electron-charges fit into that total.

Solutions written by the tuition.in editorial team and checked against the NCERT Class 10 Science textbook, Reprint 2026-27 (jesc111.pdf) — seven in-text question sets (23 questions total, not 16 as some older manifests claim) plus one end-of-chapter Exercise (18 questions, correctly counted). Unchanged by rationalisation. Table 11.2's resistivity values (used for several answers) were read directly from the book, including nichrome's 100 × 10⁻⁶ Ω·m.. Questions are referenced from the NCERT textbook for identification.