Electrostatics Assessment

Objects become negatively charged because _ . They gain electron. They lose electrons. They gain protons. They lose protons. The metal ball of the electroscope is rubbed with a negatively charged rubber rod. The electroscope becomes charged by Induction Conduction Polarization Friction Compare the charge of the electron to that of the proton Same sign, but different magnitude. Same magnitude, but different sign. Different magnitude and different sign. Same sign and same magnitude. Object 1 and 2 repel each other. Object 2 and 3 attract each other. How will object 1 and 3 interact? They will not affect each other. They will attract each other. They will repel each other. We can't know A charged balloon is brought close to a wall made up of insulating materials. The wall is electrified by induction friction contact none of the above A negatively charged rubber rod is brought close to (but not touching) the electroscope the metal leaves at the bottom move apart. Indicate the sign of the charge on the leaves Positive Neutral Negative one leaf positive and one negative As the distance between two charged objects increases, the electric force between them increases decreases stays the same all of the above Two objects A and B have different charges such that QA>QB.Compare the force exerted by A on B to the force exerted by B on A FA FA FA We can't know The electric force is a force of attraction or repulsion between objects based on their charges and their distance apart. Match the following statements. Unlike charges electric force is attractive Like charges electric force is repulsive Two balloons are charged equally with a charge Q of -0.0025 C each. They are held apart at a separation distance of 8 m. The magnitude of the electrical force between them is 7023N 878.9N 9.77x 10-8N -878.9N Two point charges each of charge of +1C are separated by a distance of 1 meter. Determine the magnitude and direction of the electrical force between them. attractive force of magnitude 9 x 109 N repulsive force of magnitude 9 x 109N attractive force of magnitude 1N repulsive force of magnitude 1N A charged metal rod is placed to the left near a neutral conducting sphere. At equlibrium, the charge of the left side (A) of the sphere is qA= + 2 x 10-15C. Answer the following three questions 1. Specify the sign of the charge of the rod positive negative neutral unknown 2. Specify the value of the charge qB of the right side (B)of the sphere zero +2 x 10-15C. -2 x 10-15C. we can't know 3. The sign of the net charge of the sphere is negative positive neutral unknown A positively charged rod is brought slowly close to the knob of an electroscope which is initially positively charged. The leaves of the electroscope will Diverge more fall down close to each others keep the same position fall down then diverge Electroscope Label the parts of the electroscope by clicking on the blue circles. knob leaves jar stem A plastic ruler is rubbed aginst a woolen cloth. What do we observe when the stick is brought close to the ball of a neutral electric pendulum The ruler repels the ball The ruler attracts the ball The ruler attracts the ball then it repels it Nothing happens because the ball is neutral Consider three identical metal spheres (A), (B) and (C) palced on a a table. The charges of the three spheres are respectively :qA=-a C,qB=+2a C,qC=4x 10-6Ca is constantWe place the three spheres in contact until electric equlibruim is attained. The charge of B becomes q'B= -2 x 10-6C. Find the constant a a=-1 x10-5 a=1x10-6 a= -7 x 10-6 none of the above Two point charges q=+5μ C and q'= -7μC are placed in air. Calculate the distance d separating these two charges knowing that they attract each others with a force of magnitude F=32.5N. d=0.01m d=0.1m d=9.6 x10-9 m d=3.09x 10-9m Two metal spheres A and B attract each others. A exrets a force on B and B exerts a force on A such that the two forces have The same line of action The same direction The same direction and line of action The same line of action and the same magnitude