Deck 11: Circuits

Question 1

The positive terminals of two batteries with emf's of ₁ and 11ef181e_322b_03c7_b5ce_15ab819e17f1_TB10137_11₂, respectively, are connected together. Here 11ef181e_322b_03c7_b5ce_15ab819e17f1_TB10137_11₁ > 11ef181e_322b_03c7_b5ce_15ab819e17f1_TB10137_11_2. The circuit is completed by connecting the negative terminals. If each battery has an internal resistance of r, the rate in watts at which electrical energy is converted to chemical energy in the smaller battery is:

A)
B)
C)
D)
E)

Answer 1

Question 2

Nine identical wires, each of diameter d and length L, are connected in series. The combination has the same resistance as a single similar wire of length L but whose diameter is:

A) 3d
B) 9d
C) d/3
D) d/9
E) d/81

Answer 2

d/3

Question 3

The current in the 5.0- $\Omega$ resistor in the circuit shown is:

A) 0.42 A
B) 0.67 A
C) 1.5 A
D) 2.4 A
E) 3.0 A

Answer 3

1.5 A

Question 4

If a circuit has L closed loops, B branches, and J junctions the number of independent loop equations is:

A) B - J + 1
B) B - J
C) B
D) L
E) L - J

Question 5

Nine identical wires, each of diameter d and length L, are connected in series. The combination has the same resistance as a single similar wire of length L but whose diameter is:

A) 3d
B) 9d
C) d/3
D) d/9
E) d/81

Question 6

Resistor 1 has twice the resistance of resistor 2. They are connected in parallel to a battery. The ratio of the thermal energy dissipation by 1 to that by 2 is:

A) 1:4
B) 1:2
C) 1:1
D) 2:1
E) 4:1

Question 7

In an antique automobile, a 6-V battery supplies a total of 48 W to two identical headlights in parallel. The resistance (in ohms) of each bulb is:

A) 0.67
B) 1.5
C) 3
D) 4
E) 8

Question 8

To make a galvanometer into an ammeter, connect:

A) a high resistance in parallel
B) a high resistance in series
C) a low resistance in series
D) a low resistance in parallel
E) a source of emf in series

Question 9

The time constant RC has units of:

A) second/farad
B) second/ohm
C) 1/second
D) second/watt
E) none of these

Question 10

A certain capacitor, in series with a resistor, is being charged. At the end of 10 ms its charge is half the final value. The time constant for the process is about:

A) 0.43 ms
B) 2.3 ms
C) 6.9 ms
D) 10 ms
E) 14 ms