Question
Physics Question on Current electricity
Given below are two statements:
Statement I : A uniform wire of resistance 80 Ω is cut into four equal parts. These parts are now connected in parallel. The equivalent resistance of the combination will be 5 Ω.
Statement II : Two resistances 2R and 3R are connected in parallel in a electric circuit. The value of thermal energy developed in 3R and 2R will be in the ratio 3 : 2.
In the light of the above statements, choose the most appropriate answer from the option given below.
Both statement I and statement II are correct
Both statement I and statement II are incorrect
Statement I is correct but statement II is incorrect
Statement I is incorrect but statement II is correct
Statement I is correct but statement II is incorrect
Solution
Statement 1 -
R = 80 Ω
R1=R2=R3=R4=20 Ω In parallel Req=420=5Ω
**Statement 2 - **
Pth=Rv2P2P1=(R1R2)=32 (where P is Power)
So, Statement I is correct but statement II is incorrect.