MHT CET20255 May 2025Evening ShiftPhysicsElectrostaticsActual
An electric dipole of length 2 cm is placed with its axis making an angle of 60^ to a uniform electric field of 10⁺⁵ ~N / C . If it experiences a torque of 9 3 Nm , the magnitude of the charge on the dipole is ( 60^ = 3 2 )
Options
- A7 10⁻³ C
- B8 10⁻³ C
- C9 10⁻³ C
- D9 2 10⁻³ C
Correct answer
C. 9 10⁻³ C
Step-by-step solution
The torque on an electric dipole in a uniform electric field is given by = pE , where is the torque, p is the electric dipole moment, E is the electric field magnitude, and is the angle between the dipole moment and field vectors. Using the given values E = 10⁵ , N/C , 2a = 0.02 , m , = 60^ , and = 9 3 , N m , we substitute into the torque equation: 9 3 = p 10⁵ 3 2 Dividing both sides by 3 : 9 = p 10⁵ 1 2 Solving for p : p = 18 10⁵ = 18 10⁻⁵ C m The electric dipole moment relates to charge by p = q 2a . Substitutin