__WORKSHEET #5 ELECTRIC POTENTIAL__**1.**Two charges +q and –q are located at points A (0,0,-2) and B(0,0,2) respectively How much work will be done in moving a test charge form point P(4,0,0) to Q(-5,0,0)

**ZERO**

**2.**If 100J of work must be done to move electric charge =4C from a place where potential is -10 V to another place where potential is V volt, find the value of V.

**V**

**A**

**– V**

**B**

**= W**

**AB**

**/q The value of V is 15 V.**

**3.**If 10J of work is to be done in moving a charge of -200C from A to B., which of the 2 points is at higher potential? What is potential difference?

**A; -0.05V**

**4.**Two point charges of 4μC and -2μC are separated by a distance of 1m in air. Calculate at what point on the line joining the 2 charges is the electric potential zero?

**2/3 m from 4 C**

**5.**What is potential at the centre of a square of each side 1.0m when 4 charges +1 x 10

^{-8}C, -2 x10

^{-8},

+3 x10

^{ -8}and +2 x 10^{-8}C are placed at 4 corners of the square.**potential is 5.1 x 10**

**2**

**V**

**6.**A point charge of 10

^{-8}C is situated at the origin of coordinates. Find the potential difference between the point A (4, 4,2) and B(1,2,2).

**potential is -15 V**

**7.**27 charged water droplets each with diameter of 2mm and a charge of 10

^{-12}C coalesce to form a single drop. Calculate the potential of bigger drop.

**Potential of the bigger drop is 81 V**

**8.**An electric field E = (20i+30j)N/C. exist in the space. If the potential at the origin is taken to be 0 , find the potential at (2m,2m) .

**potential at (2m, 2m) is -100 V**

**9.**Two point Charges of A and B of value +15μC and +9μC are kept 18cm apart in air. Calculate the work done when charge B is moved by 3 cm toward A.

**Work done is 1.35 J**

**10.**2 electrons each moving with a velocity of 10

^{6}m/s are released towards each other. What will be the closest distance of approach between them?

**2.56 x 10**

^{-10}

**m**

**11.**Setup an arrangement of 3 point charges +q , +2q and xq are separated by equal finite distances so that electric PE of the system is 0. What is x?

**Charges +q, +2q and -2q/3 at vertices of an equilateral triangle; x = -2/3**

**12.**Three charges –q ,Q and –q are placed at equal distances on a straight line. If the potential Energy of system of 3 charges is 0 then what is the ratio of Q: q?

**1:4**