JEE Mains · Physics · STD 12 - 1. Electric charges and fields
A charge of \(4\,\mu C\) is to be divided into two. The distance between the two divided charges is constant. The magnitude of the divided charges so that the force between them is maximum, will be.
- A \(1\; \mu C\) and \(3\; \mu C\)
- B \(2\; \mu C\) and \(2\; \mu C\)
- C \(0\) and \(4\; \mu C\)
- D \(1.5\; \mu C\) and \(2.5\; \mu C\)
Answer & Solution
Correct Answer
(B) \(2\; \mu C\) and \(2\; \mu C\)
Step-by-step Solution
Detailed explanation
\(F =\frac{ Kq (4- q )}{ d ^{2}}\) \(\frac{ dF }{ dq }=\frac{ K }{ d ^{2}}[4-2 q ]=0\) \(q =2\)
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
- A tuning fork of frequency \(480\, Hz\) is used in an experiment for measuring speed of sound \((\nu )\) in air by resonance tube method. Resonance is observed to occur at two successive lengths of the air column, \({\ell _1} = 30\,cm\) and \({\ell _2} = 70\,cm\). Then \(\nu\) is equal to ..... \(ms^{-1}\)JEE Mains 2019 Hard
- Two charged conducting spheres \(S_1\) and \(S_2\) of radii \(8\) cm and \(18\) cm are connected to each other by a wire. After equilibrium is established, the ratio of electric fields on \(S_1\) and \(S_2\) spheres are \(E_{S_1}\) and \(E_{S_2}\) respectively. The value of \(\dfrac{E_{S_1}}{E_{S_2}}\) is _______.JEE Mains 2026 Medium
- A body of mass \(1 kg\) begins to move under the action of a time dependent force \(\vec{F}=\left(t \hat{i}+3 t^2 \hat{ j }\right) N\). where \(\hat{i}\) and \(\hat{j}\) are the unit vectors along \(x\) and \(y\) axis. The 10.Power developed by above force, at the time \(t=2 s\). will be \(..............W\).JEE Mains 2023 Medium
- A \(dc\) source of \(emf \,E_1 = 100\,V\) and internal resistance \(r = 0.5\,\Omega ,\) a storage battery of emf \(E_2 = 90\,V\) and an external resistance \(R\) are connected as shown in figure. For what value of \(R\) no current will pass through the battery ? ................ \(\Omega\)
JEE Mains 2013 Medium - A mixture of hydrogen and oxygen has volume \(2000 \; cm ^{3}\), temperature \(300 \; K\), pressure \(100 \; kPa\) and mass \(0.76 \; g\) The ratio of number of moles of hydrogen to number of moles of oxygen in the mixture will beJEE Mains 2022 Medium
- A point charge of \(10\,\mu C\) is placed at the origin. At what location on the \(X\)-axis should a point charge of \(40\,\mu\,C\) be placed so that the net electric field is zero at \(x =2\,cm\) on the \(X\)-axis ?JEE Mains 2023 Medium
More PYQs from JEE Mains
- A circular disc has radius \(R_1\) and thickness \(T_1\). Another circular disc made of the same material has radius \(R_2\) and thickness \(T_2\). If the moment of inertia of both discs are same and \(\frac{R_1}{R_2}=2\) then \(\frac{T_1}{T_2}=\frac{1}{\alpha}\).The value of \(\alpha\) is __________ .JEE Mains 2026 Hard
- The set of values of \(a\) for which \(\lim _{x \rightarrow a}([x-5]-[2 x+2])=0\), where, \([\zeta]\) denotes the greatest integer less than or equal to \(\zeta\) is equal toJEE Mains 2023 Medium
- Given below are two statement : one is labelled as Assertion \(A\) and the other is labelled as Reason \(R\). Assertion \(A\) : When a rod lying freely is heated, no thermal stress is developed in it. Reason \(R :\) On heating the length of the rod increases. In the light of the above statements, choose the correct answer from the options given belowJEE Mains 2021 Medium
- Let \([ x ]\) be the greatest integer \(\leq x\). Then the number of points in the interval \((-2,1)\), where the function \(f(x)=|[x]|+\sqrt{x-[x]}\) is discontinuous is \(........\).JEE Mains 2023 Hard
- Let \(A\) be any \(3 \times 3\) invertible matrix. Then which one of the following is not always true ?JEE Mains 2017 Hard
- Let \(Q\) be the foot of the perpendicular from the point \(\mathrm{P}(7,-2,13)\) on the plane containing the lines \(\frac{x+1}{6}=\frac{y-1}{7}=\frac{z-3}{8}\) and \(\frac{x-1}{3}=\frac{y-2}{5}=\frac{z-3}{7}\) Then \((\mathrm{PQ})^{2}\), is equal to ..... .JEE Mains 2021 Hard