Question:
A potentiometer of length \(4\,\mathrm{m}\) and resistance \(20\,\Omega\) is connected in series to a resistor of resistance \(28\,\Omega\). If the emf of the cell is \(5\,\mathrm{V}\) and its internal resistance is \(2\,\Omega\), then the maximum potential difference that the potentiometer measures is
A potentiometer of length \(4\,\mathrm{m}\) and resistance \(20\,\Omega\) is connected in series to a resistor of resistance \(28\,\Omega\). If the emf of the cell is \(5\,\mathrm{V}\) and its internal resistance is \(2\,\Omega\), then the maximum potential difference that the potentiometer measures is
Show Hint
The maximum measurable potential difference of a potentiometer equals the potential drop across its wire:
\[
\boxed{
V_{\max}=IR_{\text{wire}}
}
\]
where
\[
I=\frac{E}{R_{\text{external}}+R_{\text{wire}}+r}.
\]
Updated On: Jul 15, 2026
- \(4\,\mathrm{V}\)
- \(3\,\mathrm{V}\)
- \(2\,\mathrm{V}\)
- \(5\,\mathrm{V}\)
Show Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Step 1: Calculate the current in the circuit.
The total resistance is
\[
R_{\text{total}}
=
20+28+2
=
50\,\Omega.
\]
Hence,
\[
I
=
\frac{E}{R_{\text{total}}}
=
\frac{5}{50}
=
0.1\,\text{A}.
\]
Step 2: Find the potential drop across the potentiometer wire. The potentiometer resistance is \[ 20\,\Omega. \] Therefore, \[ V = IR = 0.1\times20 = 2\,\text{V}. \] This is the maximum potential difference measurable by the potentiometer. Hence, \[ \boxed{2\,\text{V}} \] Therefore, \[ \boxed{(C)} \] is the correct answer.
Step 2: Find the potential drop across the potentiometer wire. The potentiometer resistance is \[ 20\,\Omega. \] Therefore, \[ V = IR = 0.1\times20 = 2\,\text{V}. \] This is the maximum potential difference measurable by the potentiometer. Hence, \[ \boxed{2\,\text{V}} \] Therefore, \[ \boxed{(C)} \] is the correct answer.
Was this answer helpful?
0
0
Top TS EAMCET Physics Questions
- A wooden box lying at rest on an inclined surface of a wet wood is held at static equilibrium by a constant force $F$ applied perpendicular to the incline. If the mass of the box is $1\,kg$, the angle of inclination is $30^{\circ}$ and the coefficient of static friction between the box and the inclined plane is $0.2$, the minimum magnitude of $\vec{F}$ is (Use $ g = 10\,m/s^2$)
- A metre scale made of steel reads accurately at $25^{\circ} C$ . Suppose in an experiment an accuracy of $0.06\, mm$ in $1\,m$ is required, the range of temperature in which the experiment can be performed with this metre scale is (coefficient of linear expansion of steel is $ 11 \times 10^{-6} /^{\circ} \, C$ )
- Consider a solenoid carrying current supplied by a DC source with a constant emf containing iron core inside it. When the core is pulled out of the solenoid, the change in current will
- A parallel beam of light of intensity \(I_0\) is incident on a coated glass plate. If \(25\%\) of the incident light is reflected from the upper surface and \(50\%\) of light is reflected from the lower surface of the glass plate, the ratio of maximum to minimum intensity in the interference region of the reflected light is
- A thermocol box has a total wall area (including the lid) of $1.0 m ^{2}$ and wall thickness of $3 cm$. It is filled with ice at $0^{\circ} C$. If the average temperature outside the box is $30^{\circ} C$ throughout the day, the amount of ice that melts in one day is [Use $K_{\text {thermocol }}=0.03 W / mK$ $.L_{\text {fusion (ice) }}=3.00 \times 10^{5} J / kg ]$
View More Questions
Top TS EAMCET Electromagnetism Questions
- An electric dipole of length \(4\,\mathrm{cm}\) is placed in a uniform electric field of intensity \(2\times10^5\,\mathrm{N\,C^{-1}}\). When the dipole is oriented at a certain angle with the electric field, it experiences a torque of \(0.2\sqrt3\,\mathrm{N\,m}\) and possesses a potential energy of \(-0.2\,\mathrm{J}\). The magnitude of each charge of the dipole is
- The electric potential at a region in terms of the coordinates \((x,y,z)\) in metre is
\[ V(x,y,z)=\left(10-3x^2-y^2-1.5z^2\right)\times10^6\ \text{V}. \]
The magnitude of the electric force acting on a charge of \(2\,\mu\text{C}\) placed at the point \((1,1,3)\,\text{cm}\) is - For a coil rotating in a uniform magnetic field, the phase difference between the magnetic flux linked with the coil and the current induced in it is
- If \(E\) and \(B\) are the magnitudes of the electric and magnetic fields respectively of a plane electromagnetic wave and \(\omega\) is its angular frequency, then the wavelength of the wave is
- If the height of a transmitting antenna is \(45\,\mathrm{m}\) and the height of the receiving antenna is \(H\), then the maximum line-of-sight distance between the two antennas is \(1\%\) of the radius of the earth. If the radius of the earth is \(6400\,\mathrm{km}\), then the value of \(H\) is
Top TS EAMCET Questions
- A bag contains $5$ red balls, $3$ black balls and $4$ white balls are drawn at random. The probability that they are not of same colour is
- If $cosec\, \theta - \cot \theta = 2017$, then quadrant in which $\theta $ lies is
- If $a$ is a unit vector, then $| a \times \hat{ i }|^{2}+| a \times \hat{ j }|^{2}+| a \times \hat{ k }|^{2}=$
- $A$ straight line makes an intercept on the $Y$-axis twice as long as that on $X$-axis and is at a unit distance from the origin. Then the line is represented by the equations
- Let $S$ and $S'$ be the foci of an ellipse and B be one end of its minor axis. If $SBS'$ is an isosceles right angled triangle then the eccentricity of the ellipse is
View More Questions