p106. q14. ch31 .Faraday's Law

1 A rectangular coil of wire has dimensions 0.24m by 0.18m. A 25T magnetic field passes

through the coil at an angle of 15 degrees from perpendicular. What is the magnetic flux

through the coil?

A 0.28 Wb

B 0.44 Wb

C 0.60 Wb

D 1.04 Wb

E 1.80 Wb

2 A square coil of wire has dimensions of 1 x 1 m in the plane of this screen. A 1T magnetic

field passes through the coil into the screen at an angle of 0 degrees from perpendicular. If

the magnetic flux decreases by 1 Wb/s, what is the voltage one would measure across a

small gap in the wire loop?

A 1 V

B 2 V

C 3 V

D 4 V

E 5 V

3 Again take a square coil of wire having dimensions of 1 x 1 m in the plane of this page. A

1T magnetic field passes through the coil into the screen at an angle of 0 degrees from

perpendicular. If the magnetic flux decreases by 1 Wb/s and the loop is now a complete

circuit, the resulting current in the loop will create an magnetic field

A into the screen

B out of the screen

C to the left

D to the right

E No current will result in the loop

4 Two parallel rods extend from a resistor of 2 Ohms. A uniform 0.8 T magnetic field makes

an angle of 60 degrees with the normal to the page. A 60 cm conducting bar 90 deg. to

the rods connects them and slides away from the resistor at 10 m/s. What is the current in

the resistor?

A 2.1 A

B 1.6 A

C 1.2 A

D 2.4 A

E 1.0 A

p106. q15. ch32. EM Induction

1 A long solenoid has 5000 turns per meter and carries a current of 20A. What is the energy

density inside the solenoid? Answer in Joules/m3.

A 1327

B 6283

C 50000

D 148

E 2.5

2 A small battery is connected in a loop circuit in series with a 1 kilo Ohm resistor and

inductor.. A switch in the circuit delivering the battery voltage which was closed is opened.

Another switch in a wire bypassing the battery and its switch is simultaneously closed so

the circuit ``discharges”. What is the inductance if the current decreases to 1/3 of its

initial value 30 micro seconds after the discharge switch is closed?

A 74 mH

B 99 mH

C 49 mH

D 62 mH

E none of the above

3 A fixed inductance of L=2.10 micro H is used in series with a variable capacitor in the

tuning circuit of a radio. What capacitance tunes the circuit for a station which broadcasts

at 6.30 MHz?

A 76 pF

B 152 pF

C 304 pF

D 608 pF

4 A small battery is connected in a loop circuit in series with a 1 kilo Ohm resistor and

inductor. A switch in the circuit is open. What is the inductance of this circuit if the current

INCREASES to 1/3 of its FINAL value in 30 micro seconds after the switch is closed?

A 74 mH

B 99 mH

C 49 mH

D 62 mH

E none of the above

p106. q16. ch33. AC Circuits

1 A transformer connected to a 30,000 rms V ac generator is to supply 345,000 V to a

transmission line. There are 80 turns in the primary coil of the transformer. The number of

turns in the secondary must be

A 6

B 70

C 920

D 9200

E 12

2 What is the net impedance in an RLC series circuit if the imposed voltage has a frequency

of =500,

R=1000 Ohms, C=1 micro F, and L=1 H?

A 600 Ohms

B 1200 Ohms

C 1800 Ohms

D 2300 Ohms

E 1100 Ohms

3 3. If a series RLC circuit has an impedance of 1000 Ohms and an imposed rms voltage of

141.4 V, what is the rms current in the circuit?

A 0.141 A

B 0.282 A

C 0.564 A

D 1.128 A

4 4. What relative values must X_L and X_C have to obtain the maximum rms I in an RLC

series circuit?

A X_L = 0.5 X_C

B X_L = X_C

C X_L = 2 X_C

D X_L = 10 X_C

5 An LC circuit is to have resonant oscillations at 5 Hz. Find the value of a capacitor which

will work with a 1.0 mH inductor.

A 2 F

B 1 F

C 0 F

D 0.1 F

p106. q17. ch34. Electromagnetic Waves

1 Light intensity is measured in units of ______

A W/m^2

B Wm^2

C m^2/W

D W^2/m

2 A light wave between the gamma and x ray types has a frequency of 10^(19) Hz. What is

its wavelength?

A 3 x 10 ^(-12) m

B 3 x 10 ^(-11) m

C 3 x 10 ^(-10) m

D 3 x 10 ^(-9) m

3 Light frequency (f) is mesured in units of ________, wavelength in ______, and they are

related to one another by ___________

A Hz; m; f=c/wavelength

B m; Hz; f=c/wavelength

C Hz; m; f=wavelength/c

D Hz; m; f=c x wavelength

4 Which of the lists below is in order of increasing wavelength, left to right

A gamma rays; x-rays; visual; infra-red

B infra-red; visual; x-rays; gamma rays;

C x-rays; gamma rays; visual; infra-red

D visual; x-rays; gamma rays; infra-red

5 Light intensity in terms of B alone is proportional to B^x where B is the amplitude of the

magnetic field oscillation of the wave. x=

A 4

B 3

C 2

D 1

p106. q18. ch35. Light & Geoptics

1 A real object is placed 10 cm from a converging lens that has a focal length of 6cm. Which

statement is most accurate?

A The image is real, erect, and enlarged.

B The image is real, inverted, and enlarged.

C The image is real, erect, and reduced.

D The image is real, inverted, and reduced.

2 What is the focal length of a lens that forms a virtual image 30cm from the lens when a

real object is placed 15cm from the lens?

A 10 cm

B 15 cm

C 30 cm

D 45 cm

3 What is the magnification of a lens that forms an image 20 cm to its right when a real

object is placed 10 cm to its left?

A 0.50

B 1.0

C 1.5

D -2.0

4 The index of refraction for water is 1.33 and that for glass is 1.50. A light ray strikes the

water/glass boundary with an incident angle of 30.00 from normal on the water side. Which

statement is most likely true for its refracted angle from normal in the glass?

A The angle of refraction is 26.30.

B The angle of refraction is 34.70.

C The angle of refraction is 30.00.

D The angle of refraction is 60.00.

5 When you get up in the morning and look at yourself in the bathroom mirror, you are

looking at a __________

A real image, behind the mirror

B virtual image, in front of the mirror

C real image, in front of the mirror

D virtual image, behind the mirror

p106. q19. ch36. Geo Optics & Opti Instruments

1 A magnifying lens has a focal length of 1cm. A person has a near point of 25cm. What is

the magnification of the lens for that person focussed at the near point?

A 1.6

B 2.6

C 26

D 56

E 106

2 A person is designing a Keplerian lens telescope which will have a magnification of ten

times. If the focal length of the objective lens is 18cm, what is the focal length of the

eyepiece?

A 0.18cm

B 1.8cm

C 18cm

D 180cm

E Impossible to tell.

3 A person is designing a Keplerian lens telescope which will have an objective which is 0.25

meters in diameter. What is the telescope's light gathering power compared to the night

adapted eye whose pupil diameter is 0.005m?

A 5x

B 25x

C 50x

D 2500x

4 A microscope objective has a focal length of 0.1 cm. If an object is placed 0.12 cm from

the objective, what is the magnification of the real image height/object height (size/size)

relative to the center of the lens?

A 1

B 2

C 3

D 4

E 5

5 Suppose an objective similar to the one in the previous question had a magnifying power of

7 of its real image/object size and the real image was examined by a 20 power magnifier

similar to question 1, earlier. What is the power of the resulting compound microscope?

A 140

B 70

C 35

D 20

E 3