JEE Mains · Physics · STD 12 - 1. Electric charges and fields
Two point charges \(2 q\) and \(q\) are placed at vertex \(A\) and centre of face CDEF of the cube as shown in figure. The electric flux passing through the cube is :
- A \(\frac{3 q}{\varepsilon_0}\)
- B \(\frac{ q }{\varepsilon_0}\)
- C \(\frac{3 q}{2 \varepsilon_0}\)
- D \(\frac{3 q}{4 \varepsilon_0}\)
Answer & Solution
Correct Answer
(D) \(\frac{3 q}{4 \varepsilon_0}\)
Step-by-step Solution
Detailed explanation
\(\phi=\frac{ Q _{\text {in }}}{\varepsilon_0}\) \(\phi=\frac{\frac{q}{4}+\frac{q}{2}}{\varepsilon_0}=\frac{3 q}{4 \varepsilon_0}\)
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
- Two strings (A, B) having linear densities \(\mu_{ A }=2 \times 10^{-4} kg / m\) and \(\mu_{ B }=4 \times 10^{-4} kg / m\) and lengths \(L _{ A }=2.5 m\) and \(L _{ B }=1.5 m\) respectively are joined. Free ends of A and B are tied to two rigid supports C and D , respectively creating a tension of 500 N in the wire. Two identical pulses, sent from \(C\) and \(D\) ends, take time \(t_1\) and \(t_2\), respectively, to reach the joint. The ratio \(t_1 / t_2\) is :JEE Mains 2026 Medium
- A hydraulic press can lift \(100\, kg\) when a mass \('m'\) is placed on the smaller piston. It can lift ......... \(kg\) when the diameter of the larger piston is increased by \(4\) times and that of the smaller piston is decreased by \(4\) times keeping the same mass \('m'\) on the smaller piston.JEE Mains 2021 Hard
- The correct match between the entries in column \(I\) and column \(II\) are \(I\) \((II)\) Radiation Wavelength \((a)\) Microwave \((i)\) \(100 m\) \((b)\) Gamma rays \((ii)\) \(10^{-15} m\) \((c)\) \(A.M.\) radio waves \((iii)\) \(10^{-10} m\) \((d)\) \(X-\)rays \((iv)\) \(10^{-3} m\)JEE Mains 2020 Medium
- The shortest wavelength of the spectral lines in the Lyman series of hydrogen spectrum is \(915\)\(A\). The longest wavelength of spectral lines in the Balmer series will be _______ \(A\).JEE Mains 2024 Hard
- A solid steel ball of diameter 3.6 mm acquired terminal velocity \(2.45 \times 10^{-2} \mathrm{~m} / \mathrm{s}\) while falling under gravity through an oil of density \(925 \mathrm{~kg} \mathrm{~m}^{-3}\). Take density of steel as \(7825 \mathrm{~kg} \mathrm{~m}^{-3}\) and g as 9.8 \(\mathrm{m} / \mathrm{s}^2\). The viscosity of the oil in SI unit isJEE Mains 2025 Medium
- Three rods of Copper, Brass and Steel are welded together to form a \(Y\) shaped structure. Area of cross - section of each rod \(= 4\ cm^2\) . End of copper rod is maintained at \(100^o C \) where as ends ofbrass and steel are kept at \(0^o C\). Lengths of the copper, brass and steel rods are \(46, 13\) and \(12\ cms\) respectively. The rods are thermally insulated from surroundings excepts at ends. Thermal conductivities of copper, brass and steel are \(0.92, 0.26\) and \(0.12\ CGS\) units respectively. Rate ofheat flow through copper rod is ....... \(cal\, s^{-1}\)JEE Mains 2014 Hard
More PYQs from JEE Mains
- If the mean and the variance of a binomial variate \(X\) are \(2\) and \(1\) respectively, then the probability that \(X\) takes a value greater than or equal to one isJEE Mains 2015 Hard
- Let \(A\) be the point of intersection of the lines \(L_1: \frac{x-7}{1}=\frac{y-5}{0}=\frac{z-3}{-1}\) and \(L_2: \frac{x-1}{3}=\frac{y+3}{4}=\frac{z+7}{5}\). Let \(B\) and \(C\) be the point on the lines \(L_1\) and \(L_2\) respectively such that \(\mathrm{AB}=\mathrm{AC}=\sqrt{15}\). Then the square of the area of the triangle ABC is :JEE Mains 2025 Medium
- A proton and a deutron ( \(\mathrm{q}=+\mathrm{e}, m=2.0 \mathrm{u})\) having same kinetic energies enter a region of uniform magnetic field \(\vec{B}\), moving perpendicular to \(\vec{B}\). The ratio of the radius \(r_d\) of deutron path to the radius \(r_p\) of the proton path is _______.JEE Mains 2024 Hard
- A particle is travelling \(4\) times as fast as an electron. Assuming the ratio of de-Broglie wavelength of a particle to that of electron is \(2: 1,\) the mass of the particle isJEE Mains 2021 Medium
- The deflection in moving coil galvanometer falls from \(25\) divisions to \(5\) division when a shunt of \(24\ \Omega\) is applied. The resistance of galvanometer coil will be :JEE Mains 2024 Hard
- The coefficient of \(x^{10}\) in the expansion of \((1 + x)^2 (1 + x^2)^3 ( 1 + x^3)^4\) is euqal toJEE Mains 2018 Hard