Exam 1, PHYS 202
Chapters 25, 26, 27, & 28
8 March 2006
Name________________________
1) In this figure, the resistances are R1=3.0 Ω and R2=1.0 Ω, and the ideal batteries
have emfs E1=1.0 V and E2=5.0 V. What are
a) size and direction (up or down) of current in battery 1______________
b) size and direction of current in battery 2
______________
c) size and direction of current in battery 3
______________
d) the potential difference Va-Vb
______________
2) In this figure, how much charge is stored on the parallel-plate capacitors by the 10
V battery? On is filled with air, and the other is filled with a dielectric for which
κ=2.00; both capacitors have a plate area of 2.50x10-3 m2 and a plate separation of
3.00 mm.
Q1=_____________ C
Q2=_____________ C
3) A 120 V potential difference is applied to a space heater whose resistance is 20 Ω
when hot.
a) At what rate is electrical energy transferred to thermal energy? ________
b) What is the cost for 6 hours at US$0.05/kW·h?
________
4) An electron has an initial velocity of (10000 ˆj + 13000kˆ)m / s and a constant
acceleration of (3.00 × 1012 m / s 2 )iˆ in a region in which uniform electric and magnetic
fields are present. If B = (400 µT )iˆ , find the electric field E .
5) In this figure, R1=200 Ω, R2=100 Ω, R3=100 Ω, R4=150 Ω, and the ideal battery has
emf E=5.00 V.
a) What is the equivalent resistance? ___________
b) What is the current in resistance 1?___________
c) What is the current in resistance 2?___________
d) What is the current in resistance 3?___________
e) What is the current in resistance 4?___________