Question

(a) A charged particle decelerates as it moves from location A to location B. If

V_A = 260 V and V_B = 140 V, what is the sign of the charged particle?

positive or negative?

Review motion of positively and negatively charged particles as they move from high to low potential or from low to high potential.
(b) A proton gains electric potential energy as it moves from point 1 to point 2. Which of the following is true regarding the electric potential at points 1 and 2?

V₁ = V₂

V₁ > V₂

V₁ < V₂

Answer 1

(a) V_A = 260 V and V_B = 140 V. A charged particle moving from location A to location B decelerates. Thus the particle is negatively charged.

A positively charged particle moving from high to low potential region accelerates where as a negatively charged particle moving from high to low potential region decelerates. For better understanding, you can look at these potentials this way, higher potential region is more positive than the lower potential region. Thus, repels the positively charged particle moving towards it, decelerating it. And a negatively charged particle moving towards high potential region is attracted towards it, because of which it gets accelerated.

(b) A proton gains electric potential energy as it moves from point 1 to 2. Which means, V = V₂ -V₁ is positive. Thus, V₁ < V_2.