Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
COMEDK202510 May 2025Evening ShiftPhysicsElectrostaticsActual

A particle ' X ' carrying a charge +Q is moving in a circular path of radius R around another particle ' Y ' having a charge -Q with a frequency ' v '. Then the mass ' m ' of the charged particle is

Options

  1. AM= Q^2 [16 ^3 ₀ R^2 v^2 ]
  2. BM= Q^2 [16 ^2 ₀ R v^2 ]
  3. CM= Q^2 [16 ^2 ₀ R^3 v^2 ]
  4. DM= Q^2 [16 ^3 ₀ R^3 v^2 ]

Correct answer

D. M= Q^2 [16 ^3 ₀ R^3 v^2 ]

Step-by-step solution

The electrostatic force between the two charges Q and -Q separated by a distance R provides the necessary centripetal force for the circular motion of particle X . The electrostatic force is given by Coulomb's law as F_ e = 1 4 ₀ Q^2 R^2 . The centripetal force required for circular motion is F_ c = m ^2 R , where is the angular frequency. Given the frequency v , the angular frequency is = 2 v . Equating the forces: 1 4 ₀ Q^2 R^2 = m (2 v)^2 R . Simplifying the equation: Q^2 4 ₀ R^2 = m (4 ^2 v^2) R . Solving for m

Practice Electrostatics on Quantrex Academy →

More from Electrostatics

A charge of 5 C is placed at the centre of a spherical shell S₁ of radius 10 cm. Now this system is enclosed inside another spherical shell S₂ of radius 20 cm. The ratio of the ele 2026Two point charges P = +25 C and Q = -16 C are placed 5 cm apart. Find the position of the point at which the resultant electric field is zero: 2026Bodies P, Q, R, S are labelled as having charges Q_P = 0.5 10⁻¹⁹C , Q_Q = 0.7 10⁻¹⁹C , Q_R = 2.1 10⁻¹⁹C , Q_S = 4.8 10⁻¹⁹C respectively. Select the body having the correct charge. 2026Uniform electric field of 5 10^3 ,NC⁻¹ is maintained in the positive Y direction. Now a point charge of 2 10⁻⁴C at rest is released from the origin. The kinetic energy attained by 2026A pith ball of mass 'm' gram and charge 'Q' is suspended using a mass less silk thread near a large charged conducting metal sheet of area 'A' and surface charged density ' '. If t 2026In a uniform electric field 10^6 N C⁻¹ an electric dipole of length 4 cm is placed with its axis making an angle 60^ with the electric field. If the dipole experiences a torque of 2026An electric field and magnetic field 1.8 10^4 Vm⁻¹ and 6 10⁻³ T respectively are applied simultaneously on an electron beam such that path of the beam remains undeviated, then the 2026A uniform electric field E = 3 i + 6 j + k passes through a closed cuboidal surface. One face of the cuboid has an area 4 m^2 and an outward unit normal given by 2 i +2 j +3 k 17 . 2026 Full Electrostatics list All COMEDK PYQs