Physics-DPP-1-Electrostatics

PHYSICS Topic: ELECTROSTATICS Date: 1. Two metallic spheres of same mass are given equal and opposite charges; then: (a) the mass the positively charged sphere increases (b) the mass of both remains the same (c) the mass of negatively charged sphere increases (d) the mass of both spheres increases 2. A charqe q is placed at the midpoint of the line joining two equal chages Q. the system of three charges will be in equilibrium when q has the value : (a) Q/4 (b) Q/2 (c) – Q/4 (d) – Q/2 3. In the adjoining figure, the electric field lines for charges q1 and q2 are shown. Identify the sign of the charges: (a) both negative (b) upper charge is negative and lower is positive (c) both positive (d) upper charge is positive and lower is negative 4. In this figure, electric field lines in a certain region are shown. The figure suggests that : (a) (c) Ex = Ey = Ez Ex > Ey = Ez (b) (d) Ex < Ey = Ez Ex = Ez < Ey 5. An electric dipole placed in non-uniform electric fieled as shown in figure, experiences (a) a force & torque (b) a force only (c) a torque only (d) Neither force nor torque 6. Two metal spheres of same mass are suspended from a common point by a light insulating string. The length of each string is same. The sphere are given electric charges + q on one end and + 4q on the other. Which of the given diagram best shows the resulting positions of sphere ? (a) (b) (c) (d) PHYSICS Topic: ELECTROSTATICS Date: 7. Infinite number of charges each of magnitude q are lying at x = 1, 2, 4, 8 metre of x - axis. The value of intensity or electric field at point x = 0 due to these charges will be : (a) 12 ´ 109 qN / C (b) zero (c) 6 ´ 109 qN / C (d) 4 ´ 109 qN / C 8. The spatial distribution of the electric field due to two charges (A, B) is shown in figure. Which one of the following statements is correct ? (a) A is + ve and B is – ve and | A | > | B | (b) A is – ve and B is + ve, | A | = | B | (c) Both are + ve bu A > B (d) Both are – ve but A > B 9. Three charges are placed at the vertices of an equilateral triangle of side a as shown in the figure. The force experienced by the charge placed at the vertex A in a direction normal to BC is : (a) Q2 4πε a2 (b) +Q2 2πε a2 (c) 3Q2 4πε a2 (d) zero 10. Four charges equal to – Q are placed at the four corners of a square and a charge q is at its centre. If the system is in equilibrium, the value of q is : (a) – Q 1 + 4 2 2) (b) Q(1 + 2 2) (c) – Q 1 + 2 2 2) (d) Q (1 + 2 2) PHYSICS Topic: ELECTROSTATICS Date: 1. (c) 2. (C) Answer Key 3. (a) 4. (d) 5. (a) 6. (a) 7. (a) 8. (a) 9. (a) 10. (b)

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