Physics 10b Practice Exam 2 v2

联系我们： 手动添加方式: 微信>添加朋友>企业微信联系人>13262280223 或者 QQ: 1483266981

Physics 10b

Practice Exam 2 v2

1) An electron is fired from the positive end of a parallel plate capacitor towards the negative with an initial speed ofv = 1.5X106 m/s. The capacitor is fully charged and connected to a 12V battery. The plates ofthe capacitor are separated by a distance d = 6mm.

a) What is the acceleration ofthe electron

b) What is the farthest distance from the positive end of the capacitor reached by the electron

c) At what distance from the positive end ofthe capacitor is the electron’s speed equal to half of its initial

speed

2) The circuit depicted in the figure has a voltage source of V = 6V,

a resistor of variable length R1, and a resistor R2 =4Ω. Given that

R1 has a resistivity of ρ = 2X10-8 Ωm and a cross sectional area

ofA = 0.01mm2, how long must R1 be such that the current

through R1 and R2 are equal

3) Three wires with equal currents and lengths are arranged as shown in the figure. Ifthe

current in the wires is I = 2A, the length of the wires is L = 3m, the separation x1 = 0.5m,

and the separation x2 = 0.2m. What is the net force on each wire

4) Two infinitely long solenoids (seen in cross section)

pass through a circuit as shown in the figure to the right.

r1 and r2 indicate the radii ofthe two solenoids. The

magnitude ofthe magnetic field inside each solenoid is

the same and is increasing at a rate of 100T/s. What is

the current in each ofthe three resistors