Chapter 11 Electricity
NCERT Class 10th
Science SOLUTIONS

An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.
Given:
Resistance (R) = 20 ohms
Current (I) = 5 amperes
Time (t) = 30 seconds
Formula:
Heat developed (H) = I² × R × t
H = 5² × 20 × 30 = 25 × 20 × 30 = 15000 joules
Hence heat developed in 30 seconds = 15000 joules
Electricity
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