All Exams Test series for 1 year @ ₹349 only
Question

Which of the following statements is correct?

This question was previously asked in
RRB NTPC 2024 Undergraduate CBT 1 Question Paper (29-Aug-2025) (Shift 1)
The correct answer is

On increasing the length of the conductor, resistance is increased.

The correct answer is: On increasing the length of the conductor, resistance is increased.

The resistance \(R\) of a conductor is directly proportional to its length (\(L\)) and inversely proportional to its cross-sectional area (\(A\)). This relationship is described by the formula:

\(R = \rho \frac{L}{A}\)

where \(\rho\) is the resistivity of the material, a constant that depends on the type of material.

From this formula, we can see that if the length \(L\) of the conductor increases while the cross-sectional area \(A\) remains constant, the resistance \(R\) will also increase proportionally. Conversely, if the length decreases, the resistance decreases. Options 2 and 4 are incorrect because they contradict this fundamental relationship. Option 3 is incorrect because increasing the thickness (which increases the cross-sectional area) actually *decreases* the resistance.

Was this answer helpful?

Similar Questions

  1. If the length of a resistor is doubled, what happens to its resistance, assuming all other factors remain constant?

  2. The resistance of a particular material wire with length L and cross-sectional area A is 2 Ω. What would be the resistance of another wire of the same material having length 2L and area of cross-section A/2?
  3. Which of the following factors affect(s) the resistance of a wire?
  4. The resistance of a uniform metallic conductor depends on its:
  5. A cylindrical wire of length L and radius r has resistance R. The resistance of another wire of the same material but of twice its length and one-fourth its radius is:

  6. A cylindrical wire of length L and radius r has a resistance R. The resistance of another wire of the same material but half its length and half its radius will be:
  7. The length and the cross-sectional area of a conductor in the shape of a cylinder are '\(l\)' and '\(A\)' respectively. The resistivity of the material of the conductor is '\(\rho\)'. Its resistance depends upon
    (p) \(l\) only
    (q) \(l\) and \(A\)
    (r) \(\rho\), \(l\) and \(A\)
    (s) \(\rho\) and \(l\), but not \(A\)
    Pick up the right option from those given above.
  8. Resistivity of the wire depends on mainly ________
  9. The resistance of a metallic wire of length 1m and area of cross-section 1sq.metre having a resistivity is $2 \times 10^{-6}$ ohm - m is:
  10. A cylindrical wire of length \(L\) and radius \(r\) has a resistance \(R\). The resistance of another wire of same material but having four times its length and half its radius will be:

Important Questions from Resistance and Resistivity

  1. Which of the following metals has the lowest electrical resistivity?

  2. When electric current is passed through a wire, the amount of heat produced in a wire depends upon _______.

    I. Length

    II. Thickness

  3. A uniform wire of resistance 9Ω is bent in the form of an equilateral triangle. Find the effective resistance across a side of the triangle.

  4. The value of carbon resistance is 54 × 103 Ω. The percentage tolerance is 5%. What is the colour code sequence of carbon resistance?

  5. Which of the following relations are wrong?

    I. The specific conductance is given by the relation \(k = \frac{1}{R}\left( {l/A} \right)\)

    II. The equivalent conducting is given by the relation \(\lambda = \frac{{100\;K}}{C}\)

    III. The specific resistance is given by the relation \(\rho = \frac{{Rl}}{A}\)

Need Expert Advice?
Upcoming Exams
RRB NTPC
September 27, 2026
RRB Technician
October 06, 2026
Test Series
RRB ALP img
Railways
RRB ALP 2026 Mock Test series
1035 Tests 1 Tests Free
1002 Attempts
4.3(238)
English, Hindi

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App