Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
MHT CET20225 Aug 2022Morning ShiftPhysicsElectrostaticsActual

Three isolated metal spheres A, B, C have radius R, 2R, 3R respectively, and the same charge, Q . U_A, U_B and U_C be the energy density just outside the surface of the spheres. The relation between U _ A , U _ B and U _ C is

Options

  1. AU _ A > U _ B < U _ C
  2. BU _ A > U _ B > U _ C
  3. CU _ A < U _ B < U _ C
  4. DU _ A U _ C

Correct answer

B. U _ A > U _ B > U _ C

Step-by-step solution

The correct option is (B). Concept: Energy density in the free space is given by, U = 1 2 ₀ E ^2 The electric field for an isolated sphere is E= Q 2 ₀ r^2 Therefore, Energy density U 1 r ^4 And, U _ A > U _ B > U _ C is the correct trend.

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 MHT CET PYQs