enEnglishguગુજરાતી
GUJCET · Physics · Current Electricity
Two wires of equal length and equal diameter and having resistivities \(\rho_1\) and \(\rho_2\) are connected in series. The equivalent resistivity of the combination is _________.
- A \(\rho_1+\rho_2\)
- B \(\frac{\rho_1+\rho_2}{2}\)
- C \(\frac{\rho_1 \rho_2}{\rho_1+\rho_2}\)
- D \(\sqrt{\rho_1 \rho_2}\)
Answer & Solution
Correct Answer
(B) \(\frac{\rho_1+\rho_2}{2}\)
Step-by-step Solution
Detailed explanation
(B)
\(R=R_1+R_2\)
\(\frac{\rho(2 l)}{ A }=\frac{\rho_1 l}{A}+\frac{\rho_2 l}{A}\)
\(\begin{array}{ll}\therefore & 2 \rho=\rho_1+\rho_2 \\ \therefore & \rho=\frac{\rho_1+\rho_2}{2}\end{array}\)
\(R=R_1+R_2\)
\(\frac{\rho(2 l)}{ A }=\frac{\rho_1 l}{A}+\frac{\rho_2 l}{A}\)
\(\begin{array}{ll}\therefore & 2 \rho=\rho_1+\rho_2 \\ \therefore & \rho=\frac{\rho_1+\rho_2}{2}\end{array}\)
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
- In the given circuit, potential difference between points \(P\) and \(Q\) is ___________ .
GUJCET 2025 Hard - An electric dipole of dipole moment \(\overrightarrow{\mathrm{P}}\) is placed parallel to the uniform electric field of intensity \(\overrightarrow{\mathrm{E}}\). On rotating it through angle of \(90^{\circ}\) from this situation, the amount of work done is ___________.GUJCET 2026 Medium
- For the which value of Resistance \(R =\) _________ when galvanometer shows zero deflection for following below electrical circuit.
GUJCET 2012 Hard - A ray coming from an object which is situated at \(O\) distance in the air and falls on a spherical glass surface ( \(n=1.5\) ) Then the distance of the image will be ________ . \(R\) is the radius of curvature of a spherical glass.GUJCET 2024 Easy
- The electric potential at the surface of an atomic nucleus (Z=50) of radius \(9 \times 10^{-15} m\) is __________.GUJCET 2006 Easy
- In an ideal step up transformer, the number of turns in primary coil and secondary coil are 100 and 200 respectively. If output current is found to be 5A, then input current will be ___________.GUJCET 2026 Easy
More PYQs from GUJCET
- Both \(\left[ Ni ( CO )_4\right]\) and \(\left[ Ni ( CN )_4\right]^{2-}\) are diamagnetic. The types of hybridisation of Ni in these complexes are _____ and _____ respectively.GUJCET 2015 Hard
- According to crystal field theory for which of the following coordination entities \(\Delta_0\) is maximum?GUJCET 2025 Medium
- If inverse matrix of \(A = \begin{bmatrix} 2 & 3 \\ 1 & -4 \end{bmatrix}\) is \(\mathrm{A}^{-1}=\left[\begin{array}{cc}a & \frac{3}{11} \\ \frac{1}{11} & b\end{array}\right]\), then \(a+b=\) ___________.GUJCET 2026 Medium
- In gel electrophoresis method __________.GUJCET 2024 Hard
- In which of the following AC circuit, we get the value of power factor 1 at resonance condition?GUJCET 2025 Hard
- Giving 'T' symbol for true statement and 'F' symbol for false statement, select suitable option from the given options for following statements.
(i) Cytosine base is the derivative of pyrimidine.
(ii) β-D ribose sugar is present in DNA.
(iii) The message for the synthesis of a specific protein is present in RNA.
(iv) DNA is responsible for maintaining the identify of different species of organisms for one century.GUJCET 2019 Hard