College Physics Test 4

Identical batteries are connected in different arrangements to the same light bulb, as shown in the figure above. For which arrangement will the bulb shine the brightest?

A

A 9 Volt battery is hooked up to two resistors in series. One has a resistance of 5 Ohms, and the other has a resistance of 10 Ohms. Several locations along the circuit are marked with letters, as shown in the figure above. Which statement about this circuit is true?

The current at A is equal to the current at B, which is equal to the current at C, which is equal to the current at D.

Which of the following units are acceptable units for current?

A & C/s

From the figure above, the resistor R has a variable resistance. As R is decreased      ?     .

I₁ decreases, I₂ increases

Identical light bulbs are attached to identical batteries, as shown in the figure above. The ranking (from lowest to highest) of the total power emitted from the light bulb(s) is      ?     .

B, A, C

Which equation determines the equivalent resistance of resistors in series?

R_{eq} = R_1 +R_2 +R_3+…

A 10.0 V battery is connected across two resistors in series. If the resistors have resistances of 840.0 ohms and 590.0 ohms, what is the voltage drop across the 590.0 ohm resistor?

4.1 V

A component with a 17 Ω resistor is rated for use at power levels not exceeding 14 W. How much current (in Amps) can safely flow through the component?

0.91

The resistivity of gold is 2.44 \times 10^{-8} \ \Omega * m at a temperature of 20°C. A gold wire, 1.8 mm in diameter and 14 cm long, carries a current of 480 ma. The power (in mW) dissipated in the wire is closest to      ?     .

0.31

A device experiences a voltage drop of 5.0 V across it while a current of 10.0 mA flows through it. How much power (in mW) does it dissipate?

50

The heater element of a 120 V toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. The resistivity of nichrome at the operating temperature of the toaster is 1.3 \times 10^{-6} \ \Omega * m. The toaster is operated at a voltage of 120 V. The power (in W) drawn by the toaster is closest to      ?     .

370

What is the current through resistor R₁ in the circuit shown above?

0.08 A

Three light bulbs, A, B, and C, have electrical ratings as follows: 

Bulb A - 96 W, 1.7 A

Bulb B - 120 V, 156 W

Bulb C - 120 V, 0.4 A 

The three bulbs are connected in a circuit, which is across a 150-V line, as shown. Assume the filament resistances of the light bulbs are constant and independent of operating conditions. From the figure above, the equivalent resistance (in ) of the circuit is closest to      ?     .

104

A 9 Volt battery is hooked up to two resistors in series. One has a resistance of 5 Ohms, and the other has a resistance of 10 Ohms. Several locations along the circuit are marked with letters, as shown in the figure above. Through which resistor is energy being dissipated at the higher rate?

The 10 Ohm resistor.

Which of the following is not a factor affecting the resistance of a conductor?

Potential difference across the conducting material

A resistor is made out of a low wire having a length L. Each end of the wire is attached to a terminal of a battery having a constant  voltage Vo. A current I flows through the wire. If the wire were cut in half, making two wires of length L/2, and both wires were attached to the battery (the end of both wires attached to one terminal, and the other ends attached to the other terminal), what would be the total current flowing through the two wires?

4I

What is the value of the unit charge of an electron?

1.6 \times 10^{-19} \ C

The resistivity of gold is 2.44 \times 10^{-8} \ \Omega *m at a temperature of 20°C. A gold wire, 0.5 mm in diameter and 44 cm long, carries a current of 380 ma. The number of electrons per second passing a given cross section of the wire, is closest to      ?     .

2.4 \times 10^{18}

A 7.0 Ω resistor is connected across the terminals of a 10.0 V battery. If 0.50 A of current flows, what is the internal resistance of the battery (in \Omega )?

13

A battery is rated that it provides 1.0 mW of power at 9.0 V when fully charged. How much current (in mA) can it deliver?

0.11

The resistors in the circuit shown in the figure above each have a resistance of 700 ohms. What is the equivalent resistance (in \Omega ) of the circuit?

700

If the length and diameter of a wire of circular cross section are both doubled, the resistance is      ?     .

halved

From the figure above, what is the power dissipated in the 2 ohm resistance in the circuit?

3.56 W

A 1.0 m length of metal wire is connected to a 1.5 V battery, and a current of  8.0 mA flows through it. What is the diameter of the wire (in \mu m)? (The resistivity of metal is 2.24 \times 10^{-8} \ \Omega * m .)

12