JEE Main 2019 (Online) 11th January Morning Slot | Electrostatics Question 114 | Physics

JEE Main 2019 (Online) 11th January Morning Slot

MCQ (Single Correct Answer)

-1

Three charges Q, + q and + q are placed at the vertices of a right-angle isosceles triangle as shown below. The net electrostatic energy of the configuration is zero, if the value of Q is :

JEE Main 2019 (Online) 11th January Morning Slot Physics - Electrostatics Question 114 English

JEE Main 2019 (Online) 11th January Morning Slot Physics - Electrostatics Question 114 English

$${{ - q} \over {1 + \sqrt 2 }}$$

+ q

$$-$$ 2q

$${{ - \sqrt 2 q} \over {\sqrt 2 + 1}}$$

JEE Main 2019 (Online) 10th January Evening Slot

MCQ (Single Correct Answer)

-1

Charges –q and +q located at A and B, respectively, constitude an electric dipole. Distance AB = 2a, O is the mid point of the dipole and OP is perpendicular to AB. A charge Q is placed at P where OP = y and y >> 2a. The charge Q experiences an electrostatic force F. If Q is now moved along the equatorial line to P' such that OP' = $$\left( {{y \over 3}} \right)$$, the force on Q will be close to - $$\left( {{y \over 3} > > 2a} \right)$$

JEE Main 2019 (Online) 10th January Evening Slot Physics - Electrostatics Question 115 English

JEE Main 2019 (Online) 10th January Evening Slot Physics - Electrostatics Question 115 English

F/3

27F

JEE Main 2019 (Online) 10th January Morning Slot

MCQ (Single Correct Answer)

-1

A charge Q is distributed over three concentric spherical shells of radii a, b, c (a < b < c) such that their surface charge densities are equal to one another. The total potential at a point at distance r from their common centre, where r < a, would be -

$${{Q\left( {{a^2} + {b^2} + {c^2}} \right)} \over {4\pi {\varepsilon _0}\left( {{a^3} + {b^3} + {c^3}} \right)}}$$

$${Q \over {4\pi {\varepsilon _0}\left( {a + b + c} \right)}}$$

$${Q \over {12\pi {\varepsilon _0}}}{{ab + bc + ca} \over {abc}}$$

$${{Q\left( {a + b + c} \right)} \over {4\pi {\varepsilon _0}\left( {{a^2} + {b^2} + {c^2}} \right)}}$$

JEE Main 2019 (Online) 10th January Morning Slot

MCQ (Single Correct Answer)

-1

Two electric dipoles, A, B with respective dipole moments $${\overrightarrow d _A} = - 4qai$$ and $${\overrightarrow d _B} = - 2qai$$ are placed on the x-axis with a separation R, as shown in the figure. The distance from A at which both of them produce the same potential is -

JEE Main 2019 (Online) 10th January Morning Slot Physics - Electrostatics Question 116 English