PHY 101 Chap 10, 12,13 HW & QUIZ

The resistance of a 25 watt bulb is ______ that of a 100 watt bulb, if both run on the same voltage. one half one fourth four times double

four times

A uniform electric field has a magnitude of 10 N/C and is directed upward. A charge brought into the field experiences a force of 5.0 N downward. The charge must be: -0.5 C. -2.0 C. -50 C. +0.5 C. +50 C.

-0.5 C

The temperature on a winter day is 19°F. What is the temperature in degrees Celsius? °C

-7.2

A 12 ohm resistor and a 24 ohm resistor are connected in series in a circuit with a 6.0 volt battery. Assuming negligible internal resistance in the battery, the current in the 12 ohm resistor will be 0.167 A. 6.0 A. 0.50 A. 0.25 A. 2.0 A.

0.167 A

An ice cube of mass 100 g and at 0°C is dropped into a Styrofoam cup containing 200 g of water at 25°C. The heat of fusion of ice is 80 cal/g and the specific heat capacity of water is 1.0 cal/(g·°C). Assuming the cup doesn't exchange any heat, the final temperature of the system will be which of the following?

0°C

An ice cube of mass 100 g and at 0°C is dropped into a Styrofoam cup containing 200 g of water at 25°C. The heat of fusion of ice is 80 cal/g and the specific heat capacity of water is 1.0 cal/(g·°C). Assuming the cup doesn't exchange any heat, the final temperature of the system will be which of the following? -10°C 0°C +10°C +2.5°C +5.0°C

0°C

Two positive charges, each of magnitude 1. 10-6 C, are located a distance of 9 cm from each other. (a) What is the magnitude of the force exerted on each charge? N

1.11 N

The temperature of 500 g of water is to be raised from 10°C to 40°C. The energy needed to do this is about:

1.5 ✕10^4 cal.

Two equal charges repel one another with a force of 4.00 10-4 N when they are 10 cm apart. If they are moved until the separation is 5.0 cm, the repulsive force will be: 1.6 10-3 N 8.00 10-4 N. 4.00 10-4 N. 2.00 10-4 N.

1.6 10-3 N

Two resistors, each having a resistance of 21 Ω, are connected in parallel. What is the equivalent resistance of this combination? Ω

10.5

An object has a temperature of 48°C. What is its temperature in degrees Fahrenheit? °F

118.4

How much heat must be removed from a 100-g block of copper to lower its temperature from 150°C to 15°C? The specific heat capacity of copper is 0.093 cal/g·C°. cal

1255.5

Two charged particles exert an electrostatic force of 13 N on each other. What will the magnitude of the force be if the distance between the two particles is increased to three times the original distance? N

13/9 N

A current of 2.6 A flows through a battery for 9 min. How much charge passes through the battery in that time? C

1404 C

How much heat must be added to 210 g of ice at 0°C to melt the ice completely? cal

16800

A household circuit rated at 120 Volts is protected by a fuse rated at 15 amps. What is the maximum number of 100 watt light bulbs which can be lit simultaneously in parallel in this circuit without blowing the fuse? 24 8 4 20 18

18

A certain kind of light bulb carries 1.5 amperes of current when connected to a 120 Volt AC circuit. What is its power rating? 100 W 240 W 80 W 180 W

180 W

An electron and a proton have charges of an equal magnitude but opposite sign of 1.60 10-19 C. If the electron and proton in a hydrogen atom are separated by a distance of 2.60 10-11 m, what are the magnitude and direction of the electrostatic force exerted on the electron by the proton? magnitude N direction

3.41e-07 NOT REPULSIVE

How much heat is required to raise the temperature of 60 g of water from 28°C to 90°C? cal

3720

The potential energy of a +4.0 10-6 C charge decreases from 0.17 J to 0.02 J when it is moved from point A to point B. What is the change in electric potential between these two points? V

37500 V

A mixture consists of 60 g of ice and 40 g of liquid water, both at 0°C. The amount of heat that must be added to melt all of the ice is about:

4800 cal

The volume of an ideal gas is increased from 1 m3 to 6 m3 while maintaining a constant pressure of 1000 Pa (1 Pa = 1 N/m2). How much work is done by the gas in this expansion? J

5000

A capacitor consisting of two parallel plates separated by 2.0 cm has a potential of 100 V on the top plate and a potential of 0 V on the bottom plate. The value of the electric field in the middle is: 500 N/C. 5.0 N/C. 5000 N/C. 200 N/C. 50 N/C.

5000 N/C

A current of 1.5 A is flowing through a resistance of 38 Ω. What is the voltage difference across this resistance? V

57 V

Three bulbs have power ratings for use on a 120 volt line: 60 watt, 100 watt and 150 watt. The one with the largest value of resistance has power rating 60 W. all have the same resistance. 150 W. 100 W.

60 W

A toaster draws a current of 6 A when it is connected to a 110-V ac line. (a) What is the power consumption of this toaster? W (b) What is the resistance of the heating element in the toaster? Ω

660 W 18.3

A 3-V battery in a simple circuit produces a current of 2.5 A through the circuit. How much power is being delivered by the battery? W

7.5 W

Two charged particles exert an electrostatic force of 1 N on each other. What will the magnitude of the electrostatic force be if the distance between the two charges is reduced to one-third of the original distance? N

9 N

A 10 µC charge is at the origin. A -5 µC charge is on the x-axis 10 cm to the right of the origin. At what point other than at infinity can a 1 µC charge be placed so that there will be no net electrostatic force on it? At one point on the x-axis to the right of the negative charge At one point between the two charges At some point off the x-axis either above or below At one point on the x-axis to the left of positive charge At no point

At one point on the x-axis to the right of the negative charge

A 1.5 V flashlight battery, a 10 ohm resistor, and a flashlight lamp are available. How should the lamp be connected in a circuit so that it would glow the brightest? Connect it in series with the resistor and battery so that the bulb is next to the negative terminal of the battery. Connect it directly to the battery; don't use the resistor. Connect it in parallel with the battery and the resistor. Connect it in series with the resistor and battery so that the bulb is next to the positive terminal of the battery.

Connect it directly to the battery; don't use the resistor.

What is the best way to ensure that a 40 watt bulb and a 60 watt bulb have the same voltage applied to them? Connect the bulbs in parallel with the power supply as follows. Connect the bulbs in series with the power supply as follows. Separately connect the bulbs to two power supplies rated at the same voltage. Can't be done: different wattage bulbs must always have different voltages.

Connect the bulbs in parallel with the power supply as follows

Two identical objects, one light colored and the other dark colored, are at the same elevated temperature, 50°C. You now plop (yes, plop) them down in a dark, much cooler room. Which object will reach the room's temperature first? Both reach room temperature at same time. light colored As strange as it seems, neither object will ever reach room temperature because energy conservation prevents the loss of energy. dark colored

DARK COLORED

The amount of heat is often measured in calories. If I add 1 calorie of heat energy to 1 gram of water, the temperature of the water will: decrease by 1°C. decrease by 1°F. stay the same since water has a very high specific heat. increase by 1°C. increase by 1°F.

INCREASED BY 1 C

When the temperature of the air in a balloon is lowered, the volume of the balloon: stays the same. decreases. increases. expands.

NOT INCREASES

Four samples of steel, lead, alcohol and glass all have the same mass and are all initially at 20°C. After 100 calories of heat is added to each sample, the final temperatures are 38.2°C for the steel, 85.6°C for the lead, 23.4°C for the alcohol, and 30°C for the glass. Which of these four materials has the largest specific heat capacity? The steel The glass The lead All have same heat capacity, since all absorbed 100 cal of heat. The alcohol

THE ALCOHOL

A 40 W bulb and a 60 W bulb are connected in series with a 120 V power source. Which of the following is true for this arrangement? The 60 W bulb is brighter than the 40 W bulb. The 40 W bulb is brighter than it would be if the 60 W bulb were replaced by a wire. The 60 W bulb is brighter than it would be if the 40 W bulb were replaced by a wire. The 40 W bulb is brighter than the 60 W bulb.

The 40 W bulb is brighter than the 60 W bulb

680 J of heat are added to 54 g of water initially at 20°C. (a) How much energy is this in calories? cal (b) What is the final temperature of the water? °C

a: 162.3 b: 23

Consider a proton and an electron placed near one another with no other objects close by. They would: accelerate toward each other. remain motionless. be pulled together at constant speed. move away from each other at constant speed. accelerate away from each other.

accelerate toward each other

Comparing the electrostatic force and the gravitational force we can say that: A: the electrostatic force falls off more rapidly with distance, the electrostatic force can be either attractive or repulsive while gravitation is only attractive and the electrostatic force is stronger. B. both have the same dependence on distance, both involve attraction and repulsion but the gravitational force is stronger. C: both have the same dependence on distance, the electrostatic force can be either attractive or repulsive while the gravitational force is only attractive, and the electrostatic force is stronger. D. both have the same dependence on distance, both involve attraction and repulsion but the electrostatic force is stronger. E. both have the same dependence on distance, the electrostatic force can be either attractive or repulsive while the gravitational force is only repulsive, and the electrostatic force is weaker.

both have the same dependence on distance, the electrostatic force can be either attractive or repulsive while the gravitational force is only attractive, and the electrostatic force is stronger

A positive charge is fixed at the origin. A negative charge is moved along the x-axis from x = 50 cm to x = 10 cm. The potential energy of the negative charge: increases. does not change. decreases.

decreases

If the distance between two spherical charged objects increases by a factor of two, then the electrical force between the objects: is half as big. does not change. increases by a factor of four. doubles. decreases by a factor of four.

decreases by a factor of four

The electrical force between any two charged objects is: dependent on the sign of the charge on each object. always attractive. always balanced by the action-reaction forces. always repulsive.

dependent on the sign of the charge on each object

Compared to the magnitude of the charge on a proton, the magnitude of the electrical charge carried by an electron is: exactly the same. is only 1/3 as large. about the same. is only 1/2 as large.

exactly the same

A 12 ohm resistor and a 24 ohm resistor are connected in series with a 6.0 V battery. The correct statement is the power dissipated in each resistor is the same. the smaller resistor carries the larger current. the current in each resistor is the same. the voltage difference between the ends of each resistor is the same.

the current in each resistor is the same

Two equal positive charges are near each other. If we increase the amount of charge on just one of them, then: (Select all that apply.) the electric field felt by the smaller charge increases. the electric field felt by both charges increases. only smaller charge feels an increased electrical force. both charges feel an increased electrical force. None of these are true.

the electric field felt by the smaller charge increases both charges feel an increased electrical force

A 12 ohm resistor and a 24 ohm resistor are connected in parallel across a 6.0 V battery. The correct statement from the following is the voltage difference between the ends of each resistor is the same. the power dissipated is the same in each resistor. the larger current is in the larger resistor. the current is the same in each resistor.

the voltage difference between the ends of each resistor is the same.