WBJEE · Physics · Electrostatics
Eleven equal point charges, all of them having a charge \(+Q\), are placed at all the hour positions of a circular clock of radius \(r\). except at the \(10 \mathrm{h}\) position. What is the clectric field strength at the centre of the clock?
- A \(\frac{Q}{4 \pi \varepsilon_{0} r^{2}}\) from the centre towards the mark 10
- B \(\frac{Q}{4 \pi \varepsilon_{0} r^{2}}\) from the mark 10 towards the centre
- C \(\frac{Q}{4 \pi \varepsilon_{0} r^{2}}\) from the centre towards the mark 6
- D Zero.
Answer & Solution
Correct Answer
(A) \(\frac{Q}{4 \pi \varepsilon_{0} r^{2}}\) from the centre towards the mark 10
Step-by-step Solution
Detailed explanation
The clock diagram is as shown below In the above diagram, charge \(+Q\) is not placed at \(10 \mathrm{h}\) position. So, net electric ficld strength at centre \(C\).…
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
- At a certain place, the horizontal component of earth's magnetic field is \(\sqrt{3}\) times the vertical component. The angle of dip at that place isWBJEE 2009 Easy
- A satellite of mass m rotates round the earth in a circular orbit of radius R. If the angular momentum of the satellite
is J, then its kinetic energy (K) and the total energy (E) of the satellite areWBJEE 2024 Easy - The equation of state of a gas is given by \(\left(p+\frac{a}{v^{3}}\right)\left(V-b^{2}\right)=c T,\) where \(p, V, T\) are pressure, volume and temperature respectively and \(a, b, c\) are constants. The dimensions of \(a\) and \(b\) are respectivelyWBJEE 2013 Easy
- A solid spherical ball and a hollow spherical ball of two different materials of densities \(\rho_{1}\) and \(\rho_{2}\) respectively have same outer radii and same mass. What will be the ratio, the moment of inertia (about an axis passing through the centre) of the hollow sphere to that of the solid sphere?WBJEE 2018 Hard
- A smooth massless string passes over a smooth fixed pulley. Two masses \(m_{1}\) and \(m_{2},\left(m_{1}>m_{2}\right)\) are tied at the two ends of the string. The masses are allowed to move under gravity starting from rest. The total external force acting on the two masses isWBJEE 2014 Easy
- The velocity of a particle executing a simple harmonic motion is \(13 \mathrm{ms}^{-1}\), when its distance from the equilibrium position \((Q)\) is \(3 \mathrm{m}\) and its velocity is \(12 \mathrm{ms}^{-1},\) when it is \(5 \mathrm{m}\) away from \(Q .\) The frequency of the simple harmonic motion isWBJEE 2017 Medium
More PYQs from WBJEE
- A liquid of bulk modulus \(k\) is compressed by applying an external pressure such that its density increases by \(0.01 \% .\) The pressure applied on the liquid isWBJEE 2017 Easy
- An atomic nucleus having low \(n / p\) ratio tries to find stability byWBJEE 2014 Easy
- The number of ways in which the letters of the word 'VERTICAL' can be arranged without changing the order of the vowels isWBJEE 2023 Easy
- \(\int \frac{\mathrm{dx}}{\sin x+\sqrt{3} \cos x}\) equals
where \(\mathrm{c}\) is an arbitrary constantWBJEE 2009 Medium - Suppose, \(\alpha, \beta, \gamma\) are the roots of the equation \(\mathrm{x}^3+\mathrm{qx}+\mathrm{r}=0(\) with \(\mathrm{r} \neq 0)\) and they are in A.P. Then the rank of the matrix \(\left(\begin{array}{lll}\alpha & \beta & \gamma \\ \beta & \gamma & \alpha \\ \gamma & \alpha & \beta\end{array}\right)\) isWBJEE 2025 Medium
- A thin rod \(A B\) is held horizontally so that it can freely rotate in a vertical plane about the end \(A\) as shown in the figure. The potential energy of the rod when it hangs vertically is taken to be zero. The end \(B\) of the rod is released from rest from a horizontal position. At the instant the rod makes an angle \(\theta\) with the horizontalWBJEE 2014 Hard