COMEDK · Physics · 17. Electrostatics
Two unlike charges of the same magnitude \(Q\) are placed at a distance \(d\). The intensity of the electric field at the middle point is the line joining the two charges is
- A zero
- B \(\frac{8 Q}{4 \pi \varepsilon_0 d^2}\)
- C \(\frac{6 Q}{4 \pi \varepsilon_0 d^2}\)
- D \(\frac{4 Q}{4 \pi \varepsilon_0 d^2}\)
Answer & Solution
Correct Answer
(B) \(\frac{8 Q}{4 \pi \varepsilon_0 d^2}\)
Step-by-step Solution
Detailed explanation
The magnitude of electric field due to charge at point \(A\) is \(E_A=|\mathbf{E}|=\frac{1}{4 \pi \varepsilon_0} \cdot \frac{Q}{\left(\frac{d}{2}\right)^2}=\frac{1}{4 \pi \varepsilon_0} \cdot \frac{4 Q}{d^2}\) Similarly,…
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 a Young's double slit experiment, the slits are separated by 0.5 mm. Fringes are obtained on a screen which is placed at distance 1 m away from the slits. When the screen is moved 7 cm farther away, the fringe width changes by 63 \(\mu\)m. The wavelength of light used in the experiment will be:COMEDK 2026 Medium
- A block of metal A is connected in series with another block of metal B such that the two metal blocks have the same area of cross sections. The thermal conductivity of metal A is K and the free end of metal A is at \(80^{\circ} \mathrm{C}\). The temperature of the interface is \(60^{\circ} \mathrm{C}\) and the free end of metal B is at \(20^{\circ} \mathrm{C}\). Assuming the two metals have the same thickness, the conductivity of metal B is:COMEDK 2025 Medium
- An incident ray is incident at an angle \(53^\circ\) on one face of a prism. It emerges at an angle of \(67^\circ\). The ray suffers a deviation of \(46^\circ\). The refractive index of the material of prism is:COMEDK 2025 Medium
- A current flows in a conductor from East to West. The direction of the magnetic field at a point above the conductor isCOMEDK 2019 Easy
- Curie-Weiss law is obeyed by ironCOMEDK 2013 Easy
- The spectrum obtained from the chromosphere of the sun at the time of total solar eclipse isCOMEDK 2013 Medium
More PYQs from COMEDK
- The equation of the lines joining the vertex of the parabola \(y^{2}=6 x\) to the point on it which have abscissa 24 areCOMEDK 2014 Easy
- In to a vessel containing pure water a clean glass tube of radius \(3.6 \times 10^{-4} \mathrm{~m}\) is held vertically with 12 cm of the tube above the water level. Now the capillary tube is moved down in to the water so that only 2 cm of its length is above the water surface. Angle of contact \(\theta\) at this position is (given surface tension of water \(=7.2 \times 10^{-2} \mathrm{Nm}^{-1}\) and \(g=10 \mathrm{~ms}^{-2}\))COMEDK 2025 Medium
- When a body moves in a circular path, no work is done by the force sinceCOMEDK 2019 Easy
- If \(\left[\begin{array}{cc}1 & -\tan \theta \\ \tan \theta & 1\end{array}\right]\left[\begin{array}{cc}1 & \tan \theta \\ -\tan \theta & 1\end{array}\right]=\left[\begin{array}{cc}a & -b \\ b & a\end{array}\right]\) thenCOMEDK 2018 Easy
- The first ionisation enthalpy of Al in \(\mathrm{kJ} \mathrm{mol}^{-1}\) is:
[Given the first ionisation enthalpy of \(\mathrm{Na}, \mathrm{Mg}\) and Si in \(\mathrm{kJ} \mathrm{mol}^{-1}\) are 497, 738 and 787 respectively]COMEDK 2025 Medium - A metallic rod of \(10 \mathrm{~cm}\) is rotated with a frequency 100 revolution per second about an axis perpendicular to its length and passing through its one end in uniform transverse magnetic field of strength \(1 \mathrm{~T}\). The emf developed across its ends is:COMEDK 2023 Medium