1.
The positive terminals of two batteries with emf's of
ε
1
and
ε
2
,
respectively, are connected together. Here
ε
1
>
ε
2.
The circuit
is completed by connecting the negative terminals to each
other. If each battery has an internal resistance of
r
, the rate
at which electrical energy is converted to chemical energy in
the smaller battery is:
A)
2
2
/ 2
r
ε
B)
(
)
1
2
2
/ 2
r
ε
ε
ε
−
C)
2
1
/
r
ε
D)
(
)
1
2
2
/
r
ε
ε
ε
−
E)
2
1
/ 2
r
ε
2.
A loop of wire carrying a current of 2.0 A is in the shape of a
right triangle with two equal sides, each 15 cm long. A 0.7 T
uniform magnetic field is parallel to the hypotenuse. The
total magnetic force on the two sides has a magnitude of:
A)
0.21 N
B)
0.51 N
C)
0.41 N
D)
0
E)
0.30 N
3.
A portion of a circuit is shown, with the values of the
currents given for some branches.
What is the direction and
value of the current
i
?
A)
↑
, 2A
B)
None of these
C)
↑
, 1A
D)
↓
, 2A
E)
↓
, 1A
4.
You wish to triple the rate of energy dissipation in a heating
device. To do this you could triple:
Version 1
Page 1
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '07
 Haglund
 Physics, Resistance, Magnetic Field, Electric charge

Click to edit the document details