Question

27) The figure shows a potential contour plot. If an electron was given a shove at point b, and then continued on to point a, which statement is correct? -50 V -25 V -75 V -100 V -50 v OV d A) Its potential energy will increase as it moves to a region of lower potential B) Its potential energy will decrease as it moves to a region of lower potential C) Its potential energy will increase as it moves to a region of higher potential D) Its potential energy will decrease as it moves to a region of higher potential E) Its potential energy will not change + 25 V 28) The figure shows a potential contour plot. If a proton was given a shove at point b, and then continued on to point a, which statement is correct? -50 V -25 V -75 V - 100 V -50 V OV A) Its potential energy will increase as it moves to a region of lower potential B) Its potential energy will decrease as it moves to a region of lower potential C) Its potential energy will increase as it moves to a region of higher potential D) Its potential energy will decrease as it moves to a region of higher potential E) Its potential energy will not change + 25 V

Answer 1

The relation between electric field and electric potential is dV E = dr Potential decreases in the direction of electric field. Since Va<V6 AV = V-V= negative Therefore the direction of electric field is from b to a When electron was given a shove at point b to point a , it moves towards the lower potential AU = 24V for electron 9 = -e So 4U = -AV 4V = negative AU = positive Therefore its potential energy will increase as it moves to a region of lower potential Option A correct 28. When proton was given a shove from b to a then the force on it act in the electric field direction and field direction is in the decreasing potential therefore proton moves towards the decreasing potential AU = 24V Va<V AV = Va-Vo = negative

for proton q = te So AU = + AV AU = negative Therefore potential energy will decrease for proton as it moves to a region of lower potential Option B correct