Question 1

A dielectric material such as paper is inserted between the plates of a capacitor as the capacitor holds a fixed charge on its plates. What happens to the electric field between the plates as the
Dielectric is inserted?

Accepted Answer

A)  There is no change in the field. 
B)  The field becomes weaker. 
C)  The field reduces to zero. 
D)  The field becomes stronger.

Question 2

What must be your average speed in order to travel 350 km in 5.15 h?

Accepted Answer

A)  66.0 km/h 
B)  69.0 km/h 
C)  68.0 km/h 
D)  67.0 km/h

Question 3

Two solenoids are close to each other, as shown in the figure, with the switch S open. When the switch is suddenly closed, which way will the induced current flow through the galvanometer in
The left-hand solenoid?

Accepted Answer

A)  from left to right 
B)  from right to left 
C)  There will be no induced current through the galvanometer.

Question 4

If a woman weighs 125 lb, her mass expressed in kilograms is x kg, where x is

Accepted Answer

A)  greater than 125. 
B)  less than 125.

Question 5

A 1.53-kg piece of iron is hung by a vertical ideal spring. When perturbed slightly, the system is moves up and down in simple harmonic oscillations with a frequency of 1.95 Hz and an amplitude
Of 7.50 cm. If we choose the total potential energy (elastic and gravitational) to be zero at the
Equilibrium position of the hanging iron, what is the total mechanical energy of the system?

Accepted Answer

A)  0.955 J 
B)  0.633 J 
C)  0.844 J 
D)  0.646 J 
E)  0.000 J

Question 6

A 10-kg rock and a 20-kg rock are dropped at the same time and experience no significant air resistance. If the 10-kg rock falls with acceleration  a , what is the acceleration of the 20-kg rock?

Accepted Answer

A)   4a 
B)   2a 
C)   a/4 
D)   a/2 
E)   a

Question 7

As more resistors are added in series to a constant voltage source, the power supplied by the source

Accepted Answer

A)  does not change. 
B)  decreases. 
C)  increases. 
D)  increases for a time and then starts to decrease.

Question 8

An ideal Carnot air conditioner operates between an indoor temperature of 20°C and an outdoor temperature of 39°C. How much energy does it use to remove 2000 J of heat from the interior of
The house?

Accepted Answer

A)  340 J 
B)  780 J 
C)  105 J 
D)  130 J 
E)  520 J

Question 9

The current definition of the standard second of time is based on

Accepted Answer

A)  the frequency of radiation emitted by cesium atoms. 
B)  the oscillation of a particular pendulum kept in France. 
C)  the duration of one year. 
D)  the earth's rotation rate.

Question 10

A jet plane is launched from a catapult on an aircraft carrier. In 2.0 s it reaches a speed of 42 m/s at the end of the catapult. Assuming the acceleration is constant, how far did it travel during those
2)0 s?

Accepted Answer

A)  24 m 
B)  42 m 
C)  16 m 
D)  84 m

Question 11

A generator produces 60 A of current at 120 V. The voltage is usually stepped up to 4500 V by an ideal transformer and transmitted through a power line of total resistance 1.0 Ω. Find the number
Of turns in the secondary if the primary has 200 turns.

Accepted Answer

A)  4500 
B)  5 
C)  7500 
D)  200

Question 12

Salt water is denser than fresh water. A ship floats in both fresh water and salt water. Compared to the fresh water, the volume of water displaced in the salt water is

Accepted Answer

A)  the same. 
B)  more. 
C)  less. 
D)  Cannot be determined because we do not know the volume of the ship.

Question 13

Two objects are dropped from a bridge, an interval of 1.0 s apart. Air resistance is negligible. During the time that both objects continue to fall, their separation

Accepted Answer

A)  stays constant. 
B)  increases at first, but then stays constant. 
C)  decreases. 
D)  decreases at first, but then stays constant. 
E)  increases.

Question 14

A flat coil is in a uniform magnetic field. The magnetic flux through the coil is greatest when the plane of its area is

Accepted Answer

A)  at 45° with the magnetic field. 
B)  parallel to the magnetic field. 
C)  perpendicular to the magnetic field.

Question 15

What is the voltage drop across a 5.0-Ω resistor if the current through it is 5.0 A?

Accepted Answer

A)  25 V 
B)  100 V 
C)  4.0 V 
D)  1.0 V

Question 16

A piano wire of linear mass density 0.0050 kg/m is under a tension of 1350 N. What is the wave speed in this wire?

Accepted Answer

A)  1040 m/s 
B)  520 m/s 
C)  130 m/s 
D)  260 m/s

Question 17

A waiter fills your water glass with ice water (containing many ice cubes) such that the liquid water is perfectly level with the rim of the glass. As the ice melts,

Accepted Answer

A)  the liquid-water level decreases. 
B)  the liquid-water level remains flush with the rim of the glass. 
C)  the liquid water level rises, causing water to run down the outside of the glass.

Question 18

A resistor and an inductor are connected in series to a battery. The battery is suddenly removed from the circuit and replaced by a wire to complete the circuit. The time constant for of the new
Circuit represents the time required for the current to decrease to

Accepted Answer

A)  63% of the original value. 
B)  37% of the original value. 
C)  75% of the original value. 
D)  25% of the original value. 
E)  zero.

Question 19

The secondary coil of an ideal neon sign transformer provides 7500 V at 10.0 mA. The primary coil operates on 120 V. What current does the primary draw?

Accepted Answer

A)  0.160 A 
B)  0.625 mA 
C)  0.625 A 
D)  1.66 A

Question 20

A train starts from rest and accelerates uniformly until it has traveled  2.1 km and acquired a forward velocity of  24 m/s. The train then moves at a constant velocity of  24 m/s for  400 s. The train then slows down uniformly at  until it is brought to a halt. The distance traveled by the train while slowing down is closest to

Accepted Answer

A)   4.4 km. 
B)   3.6 km. 
C)   4.2 km. 
D)   4.0 km. 
E)   3.8 km.

Exam 2: Describing Motion: Kinematics in One Dimension

A dielectric material such as paper is inserted between the plates of a capacitor as the capacitor holds a fixed charge on its plates. What happens to the electric field between the plates as the Dielectric is inserted?

What must be your average speed in order to travel 350 km in 5.15 h?

Two solenoids are close to each other, as shown in the figure, with the switch S open. When the switch is suddenly closed, which way will the induced current flow through the galvanometer in The left-hand solenoid?

If a woman weighs 125 lb, her mass expressed in kilograms is x kg, where x is

A 10-kg rock and a 20-kg rock are dropped at the same time and experience no significant air resistance. If the 10-kg rock falls with acceleration a , what is the acceleration of the 20-kg rock?

As more resistors are added in series to a constant voltage source, the power supplied by the source

An ideal Carnot air conditioner operates between an indoor temperature of 20°C and an outdoor temperature of 39°C. How much energy does it use to remove 2000 J of heat from the interior of The house?