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QJEEM24Ph7e19: JEE Main 2024 Physics - Class 12 JEEM24Ph7e19 Solution: In the given circuit, the current flowing through the…

In the given circuit, the current flowing through the resistance 20Ω20 \Omega is 0.3 A0.3 \mathrm{~A} , while the ammeter reads 0.9 A0.9 \mathrm{~A} . The value of R1\mathrm{R}_1 is _________ Ω\Omega .

JEE Main 2024 (Online) 29th January Evening Shift Physics - Current Electricity Question 38 English

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JEE Main 2024 (Online) 29th January Evening Shift Physics - Current Electricity Question 38 English Explanation

Given, i1=0.3 A,i1+i2+i3=0.9 A\mathrm{i}_1=0.3 \mathrm{~A}, \mathrm{i}_1+\mathrm{i}_2+\mathrm{i}_3=0.9 \mathrm{~A}

So, VAB=i1×20Ω=20×0.3 V=6 V\mathrm{V}_{\mathrm{AB}}=\mathrm{i}_1 \times 20 \Omega=20 \times 0.3 \mathrm{~V}=6 \mathrm{~V}

amp;i2=6 V15Ω=25 Aamp;i1+i2+i3=910 Aamp;310+25+i3=910amp;710+i3=910amp;i3=0.2 Aamp;So,i3×R1=6 Vamp;(0.2)R1=6amp;R1=60.2=30Ω\begin{aligned}& \mathrm{i}_2=\frac{6 \mathrm{~V}}{15 \Omega}=\frac{2}{5} \mathrm{~A} \\& \mathrm{i}_1+\mathrm{i}_2+\mathrm{i}_3=\frac{9}{10} \mathrm{~A} \\& \frac{3}{10}+\frac{2}{5}+\mathrm{i}_3=\frac{9}{10} \\& \frac{7}{10}+\mathrm{i}_3=\frac{9}{10} \\& \mathrm{i}_3=0.2 \mathrm{~A} \\& \mathrm{So}, \mathrm{i}_3 \times \mathrm{R}_1=6 \mathrm{~V} \\& (0.2) \mathrm{R}_1=6 \\& \mathrm{R}_1=\frac{6}{0.2}=30 \Omega\end{aligned}

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