Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app

JIPMER 2013

Exam: JIPMER
Year: 2013
Subject: Physics
Chapter: Current Electricity

JIPMER 2013 · Physics · Current Electricity

A uniform wire of resistance R and length L is cut into four equal...

A uniform wire of resistance

R

and length

L

is cut into four equal parts, each of length

L / 4

which are then connected in parallel combination. The effective resistance of the combination will be

Options

A $R$
B $4 R$
C $\frac{R}{4}$
D $\frac{R}{16}$

Correct answer

D. $\frac{R}{16}$

Step-by-step solution

\begin{array}{ll}R=\frac{\rho l}{A} \text{ or } R \propto l \\ \therefore & \frac{R_1}{R_2}=\frac{I_1}{I_2}=\frac{L}{L / 4}=4 \\ \text{ or } & R_2=\frac{R}{4}\left(\because R_1=R\right)\end{array}

In parallel combination of such four resistance

\frac{1}{R^{\prime}}=\frac{1}{R_2}+\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_2}

or

\quad \frac{1}{R^{\prime}}=\frac{1}{R / 4}+\frac{1}{R / 4}+\frac{1}{R / 4}+\frac{1}{R / 4}

or

\quad \frac{1}{R^{\prime}}=\frac{4}{R}+\frac{4}{R}+\frac{4}{R}+\frac{4}{R}

or

\quad \frac{1}{R^{\prime}}=\frac{16}{R}

or $\quad R^{\prime}=R / 16

Practice Current Electricity on Quantrex Academy →

More from Current Electricity

A potentiometer wire of 400\ cm length has a resistance of 20\ Ω . It is connected in… MHT CET Medical 2026 In the following figure current I equal to MHT CET Medical 2026 The range of voltmeter is 10\ V and its resistance is 50\ Ω . To convert it to a… MHT CET Medical 2026 When a galvanometer is shunted with a 2\ Ω resistance, the deflection is reduced to… MHT CET Medical 2026 A galvanometer can be converted into a voltmeter of certain range by connecting a… MHT CET Medical 2026 A resistance is to be measured using a meter bridge; the student chooses the standard… MHT CET Medical 2026 Which of the following statements is FALSE? A. In a balanced Wheatstone bridge, if the… MHT CET Medical 2026 A potentiometer wire has length 4 m and resistance 8\ Ω . The resistance that must be… MHT CET Medical 2026 Full Current Electricity list All JIPMER PYQs