Download A series circuit consists of a battery with internal resistance r

Phys102
Term: 131
Online HW-Ch27-Lec01
Q1:
A series circuit consists of a battery with internal resistance r and an external resistor
R. If these two resistances are equal (r = R) then the thermal energy generated per
unit time by the internal resistance r is:
A.
B.
C.
D.
E.
the same as by R
half that by R
twice that by R
one-third that by R
unknown unless the emf is given
Ans:
A
Q2:
In the diagram, the current in the 3-Ohm resistor is 4A. The potential difference
V2 − V1 is: (Give the answer in three significant figures and SI units)
1
Ans:
𝟑𝛀
i
𝟐𝛀
𝟐
V2 − V1 = −(3 + 2) × I = −20.0 V
Q3:
What is the value of the EMF that supplies the resistors, if the current flowing in the
circuit is I = 2A R1 = 40 Ω, R 2 = 10 Ω and R 3 = 50 Ω ? (Give the answer in three
significant figures and SI units)
Ans:
E − R 2 I − R1 I − R 3 I = 0
E = I(R1 + R 2 + R 3 )
= 2 × (40 + 10 + 50)
E = 200 V
KFUPM-Physics Department
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