Three equal point charges are placed at three of the comers of a square of side
ID: 582368 • Letter: T
Question
Three equal point charges are placed at three of the comers of a square of side d as shown in the figure. Which of the arrows shown represents the direction of the net electric field at the vacant comer of the square? For an electron moving in a direction opposite to the electric field its potential energy increases and its electric potential decreases. its potential energy decreases and its electric potential increases. its potential energy increases and its electric potential increases. its potential energy decreases and its electric potential decreases. both its potential energy and it electric potential remain constant. A number of resistors are connected across points A and B as shown in the figure. What is the equivalent resistance between points A and B? Three particles travel through a region of space where the magnetic field is out of the page, as shown in the figure. The electric charge of each of the three particles is, respectively, 1 is neutral, 2 is negative, and 3 is positive. 1 is neutral, 2 is positive, and 3 is negative. 1 is positive, 2 is neutral, and 3 is negative. 1 is positive, 2 is negative, and 3 is neutral. 1 is negative, 2 is neutral, and 3 is positive.Explanation / Answer
1) B)B
magnitude of electric field due to negative charge = k*q^2/d^2 (towards negative charge)
the two electric fields are perpendicualr to each other.
so, E12 = sqrt(2)*k*q^2/d^2
magnetic fields due to positive charge, E3 = k*q/(2*d^2) (radially outward)
so, Enet = E12 - E23
= sqrt(2)*k*q/d^2 - 0.5*k*q/d^2
= 0.9142*k*q/d^2
2) B)
as it moves opposite to electric field its kinetic energy increases, because it is accelerated opposite to electric field.so, potential energy must be decreased.
3) C)8 ohms
Rnet = 2 + 6*(2+2+4+2+2)/(6+2+2+4+2+2) + 2
= 8 ohms
4) E) 1 is negative,2 is nutral and 3 is positive.
use right rule :
take your fingers in the direction of velocity and curl towards magnetic field, then thumb indictaes magnetic force direction or deflection direction for a posotive charge.
F = q*(v cross B)
for particle 2 no deflection. so, it is neutral.
partcile 3 is positive as explaned above
particle 1 is negative. because it is deflected opposite to particle 3.