Exams › JEE Advanced › Physics
Eight identical conducting droplets, each of radius r and potential 1 V, are combined to form a single large drop. What is the potential (in V) of the large drop?
- 1 V
- 2 V
- 4 V
- 8 V
Correct answer: 4 V
Solution
8 small drops merge: total volume conserved gives R = 8^(1/3) * r = 2r. Total charge Q = 8q. Potential of big drop = kQ/R = k(8q)/(2r) = 4(kq/r) = 4 x 1 = 4 V.
Related JEE Advanced Physics questions
- A particle with charge -q and mass m revolves in a circular path of radius r around an infinitely long charged wire with linear charge density +λ. What is the time period of its motion?
- What is the value of the electrostatic potential at point H?
- The electric potential V varies with distance x from a fixed point as follows: V = 5 V for 0 <= x < 10 m, then V decreases linearly from 5 V at x = 10 m to -10 V at x = 20 m. The electric field at x = 13 m is:
- Two capacitors are connected in a circuit with two batteries and a switch S. The system is in steady state with S open. When S is closed, which of the following statements correctly describes the energy exchange?
- In a capacitor bridge circuit, four capacitors C1, C2, C3, and C4 are connected in a bridge configuration with an EMF source E. Capacitor C1 is in the top-left arm, C2 in the top-right arm, C3 in the bottom-left arm, and C4 in the bottom-right arm. Points P and Q are the mid-points (junctions). Find the potential difference V_P - V_Q.
- An isolated charged spherical soap bubble of radius r has the pressure inside equal to atmospheric pressure outside. The surface tension of the soap solution is T. If the total charge on the bubble can be written as N*pi*r*sqrt(2*T/epsilon0), find the integer value of N.
⚔️ Practice JEE Advanced Physics free + battle 1v1 →