Question 9 ā€” Which LED will glow - Questions at the end of the chapter - Chapter 4 Class 8 - Electricity: Magnetic & Heating Effects(Curiosity)

Last updated at July 13, 2026 by

Q 9
Question

In Fig. 4.11, beaker (a) has copper and iron in lemon juice, and beaker (b) has copper and iron in pure water. In which case will the LED glow when the switch is closed?

šŸ”— Concept: 4.3.1 Voltaic Cell

Show answer Hide answer
The LED glows only in beaker (a), with lemon juice.

Explanation

  • Lemon juice is an electrolyte, so it helps make current.
  • So the cell in beaker (a) works and the LED glows.
  • Pure water is not a good electrolyte, so beaker (b) makes almost no current.
  • So the LED in beaker (b) does not glow.
An electrolyte like lemon juice is needed to make current.
Remove Ads
Maninder Singh's photo - Co-founder, Teachoo

Made by

Maninder Singh

CA Maninder Singh is a Chartered Accountant with 16+ years of practical experience and 20+ years of teaching experience. He teaches Science, Economics, Accounting and English at Teachoo using clear explanations and exam-focused methods students can trust.

For faster and distraction-free study, students can choose Teachoo Black.