MHT CET · Physics · Current Electricity
A potentiometer wire of length \(4 \mathrm{~m}\) and resistance \(5 \Omega\) is connected in series with a resistance of \(992 \Omega\) and a cell of e.m.f. \(4 \mathrm{~V}\) with internal resistance \(3 \Omega\). The length of \(0.75 \mathrm{~m}\) on potentiometer wire balances the e.m.f. of
- A \(4.00 \mathrm{mV}\)
- B \(3.75 \mathrm{mV}\)
- C \(3.00 \mathrm{mV}\)
- D \(2.50 \mathrm{mV}\)
Answer & Solution
Correct Answer
(B) \(3.75 \mathrm{mV}\)
Step-by-step Solution
Detailed explanation
\(\therefore \quad\) Total Resistance:
\(
\mathrm{R}=992+5+3=1000 \Omega
\)
Voltage across \(4 \mathrm{~m}\) wire:
\(
\frac{5}{995+5} \times 4=0.02 \mathrm{~V}
\)
\(\therefore \quad\) For one metre wire:
\(
\frac{0.02}{4}=0.005 \mathrm{~V}
\)
\(\therefore \quad\) For \(0.75 \mathrm{~m}\) wire:
\(
\begin{aligned}
0.004 \times 0.75 & =0.00375 \\
& =3.75 \mathrm{mV}
\end{aligned}
\)
\(
\mathrm{R}=992+5+3=1000 \Omega
\)
Voltage across \(4 \mathrm{~m}\) wire:
\(
\frac{5}{995+5} \times 4=0.02 \mathrm{~V}
\)
\(\therefore \quad\) For one metre wire:
\(
\frac{0.02}{4}=0.005 \mathrm{~V}
\)
\(\therefore \quad\) For \(0.75 \mathrm{~m}\) wire:
\(
\begin{aligned}
0.004 \times 0.75 & =0.00375 \\
& =3.75 \mathrm{mV}
\end{aligned}
\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- For occurring total internal reflection, which one of the following is correct statement?
\(\text { (i = angle incidence, } \mathrm{i}_{\mathrm{C}}=\text { critical angle). }\)MHT CET 2022 Easy - An observer moves towards a stationary source of sound, with a velocity one-fifth of the velocity of sound. What is the percentage increase in the apparent frequency?MHT CET 2008 Medium
- The inductive reactance of a coil is ' \(\mathrm{X}_{\mathrm{L}}\) '. If the inductance of a coil is tripled and frequency of a.c. supply, is doubled, then the new inductive reactance will beMHT CET 2023 Medium
- Magnetic susceptibility of a paramagnetic substance isMHT CET 2019 Easy
- In an adiabatic process, the state of a gas is changed from \(P_1, V_1, T_1\) to \(P_2, V_2, T_2\). Out of the following relations, the correct one isMHT CET 2022 Easy
- A magnetizing field of 500 A/m produces a magnetic flux of Wb in an iron rod of cross-sectional area . The permeability of the rod in W/b/A-m isMHT CET 2019 Medium
More PYQs from MHT CET
- How many of the following genotypes possibly represent normal wings in Drosophila?
(i) \(Vg ^{+} Vg ^{+}\)
(ii) \(Vg ^{+} v g n i\)
(iii) \(Vg ^{+}\)vgno
(iv)\(Vg ^{+} vgst\)
(v)\(Vg ^{+} vg\)MHT CET 2020 Hard - If \(y=\cos \left(\sin x^2\right)\), then \(\frac{d y}{d x} a t x=\sqrt{\frac{\pi}{2}}\) isMHT CET 2022 Easy
- If \(A\) and \(B\) are non-singular matrices of order 2 such that \((\mathrm{AB})^{-1}=\frac{1}{6}\left[\begin{array}{cc}-7 & -3 \\ 2 & 3\end{array}\right]\) and \(\mathrm{A}^{-1}=\frac{1}{3}\left[\begin{array}{cc}4 & 3 \\ -1 & 0\end{array}\right]\) then \(\mathrm{B}^{-1}=\)MHT CET 2025 Medium
- The variance of first 10 multiples of 3 isMHT CET 2022 Easy
- If \(y=\log _{\cos x} \sin x\), then \(\frac{d y}{d x}\) is equal toMHT CET 2007 Easy
- The value of \(4 \cos ^3 20^{\circ}\) isMHT CET 2022 Easy