Joule heat H=I²Rt. Maximum errors in resistance, current and time are respectively 1%, 2% and 1%. Find maximum percentage error in H.
Physics · Mixed Chapter
JEE Main Practice

Question

Joule heat H=I²Rt. Maximum errors in resistance, current and time are respectively 1%, 2% and 1%. Find maximum percentage error in H.

G1 Physics · Accepted Answer

Step 1: Joule heating relation H=I²Rt. Step 2: For a product of measured quantities, maximum fractional error is δH/H=2δI/I + δR/R + δt/t. Step 3: With current error 2%, resistance error 1% and time error 1%, δH/H in percentage=2×2 + 1 + 1=6%.