An electric field E10 NC is tilted at 45 to a square surface of area 1 m2' What is the electric flux

1
An electric field E10 N/C is tilted at 45º to a
square surface of area 1 m2.What is the electric
flux through the surface?
This PowerPoint file has all clicker questions
that are counted. Clicker question, Sept 2, 2009,
PH 106
E

• 0
• 3.54Nm2/C
• 7.07 Nm2/C
• 10.0 Nm2/C
• 14.1 Nm2/C

2
For which of the following charge configurations
could you NOT calculate the electric field from
Gauss Law?
Clicker question, Sept. 4, 2009

• A point charge
• A uniformly charged sphere
• An infinite line charge
• A finite line charge
• An infinite plane charge

3
If the potential increases to the right (along
the positive x axis) as V (15 v/m) x, the
electric field component Ex is
Clicker Question, Sept. 11, 2009

• 15 v/m
• -15 v/m
• 7.5 v/m
• -7.5v/m
• 30 v/m

4
Find the potential (in V) half way between a
charge 1 mC and a charge 2 mC that are 2 m
apart. First give the mantissa, rounded to an
integer (e.g., 6 if answer is 5.6x108 ) .
Clicker question, Sept. 14

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5
Now give the exponent (e.g., 8 in 3x108 ).
(Problem was Find the potential (in V) half
way between a charge 1 mC and a charge 2 mC that
are 2 m apart. )
Clicker question, Sept 14, 2009

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6
If we charge a 2500 mfd capacitor to 90 volts,
what is the total charge stored, in coulombs?
Use Mx10E notation, first give M
Clicker question, Sept 16, 2009

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7
Now give exponent E, in Mx10E Question was If
we charge a 2500 mfd capacitor to 90 volts, what
is the total charge stored, in coulombs?
Clicker question, Sept 16, 2009

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8
What is the total capacitance of a parallel
combination of two 100 pf capacitors? Mantissa
first
Clicker question , Sept 16, 2009

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9
What is the total capacitance of a parallel
combination of two 100 pf capacitors? exponent
Clicker question , Sept 16, 2009

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10
Consider the capacitor combination shown.
Compute the effective capacitance between the
dots, in mf. Use Mx10E notation, first give M
Clicker question, Sept. 18, 2009
100 mf

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100 mf
200 mf
11
Now give exponent E, in Mx10E
Clicker question, Sept. 18, 2009
100 mf

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100 mf
200 mf
12
The spherical top electrode of a van de Graaff
generator is at V 200,000 volts, and it is
connected to ground (V0) by a high-resistance
support column through which its charge leaks off
at the rate of 40 mC/s. What is the resistance
of this support column? First give the
mantissa, rounded to an integer (e.g., 6 if
answer is 5.6x108 ) .
Clicker question, Sept 25, 2009

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13
Now give the exponent (e.g., 8 in 3x108 ).
Clicker question

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14
A copper wire is 1 mm square in cross-section and
100 m long. The resistivity of copper is 1.7 x
10-8 Wm. Find the resistance of the wire.
First give the mantissa, rounded to an integer
(e.g., 6 if answer is 5.6x108 ) .
Clicker question, Sept 25, 2009

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15
Now give the exponent (e.g., 8 in 3x108 ).
(Problem was A copper wire is 1 mm square in
cross-section and 100 m long. The resistivity of
copper is 1.7 x 10-8 Wm. Find the resistance of
the wire.)
Clicker question, Sept. 25

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16
An electron approaches the earth with velocity
6x107 m/s, perpendicular to the earths field
(B0.5G 5x10-5 T) . What is the radius of its
orbit? Mantissa
Clicker question
Oct 7, 2009

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17
An electron approaches the earth with velocity
6x107 m/s, perpendicular to the earths field
(B0.5G 5x10-5 T) . What is the radius of its
orbit? Exponent

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18
If magnetic moment is defined as I A, what units
does it have?
Oct 12, 2009

• N/C
• A m3
• A m2
• V/m
• A m

19
A long straight wire carries a current 6A. What
is the magnetic field strength at a distance 0.5m
from the wire? Mantissa first
Oct 14, 2009 __ NOT usable

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20
The equation giving the field produced by a
current element I ds is called
Clicker question Oct 16

• Amperes law
• Gauss Law
• Coulombs law
• The law of Griot and Saban
• The law of Biot and Savart
• The law of Idiot and Savant

21
The field at a distance 1 mm 1e-6 m from a very
thin long straight wire carrying 20A is 4T. If
we move away to 2 mm and double the current to
40A, the field will be
Clicker question, Oct 16

• 1 T
• 2 T
• 3 T
• 4 T
• 5 T
• 6 T
• 7 T
• 8 T
• 9 T
• 0 T

22
The equation giving the field produced by a
current element I ds is called
Clicker question, Oct 19, 2009

• Amperes law
• Gauss Law
• Coulombs law
• The law of Griot and Saban
• The law of Biot and Savart
• The law of Idiot and Savant

23
The field at a distance 1 mm 1e-6 m from a very
thin long straight wire carrying 20A is 4T. If
we move away to 2 mm and double the current to
40A, the field will be
Clicker question, Oct 19

• 1 T
• 2 T
• 3 T
• 4 T
• 5 T
• 6 T
• 7 T
• 8 T
• 9 T
• 0 T

24
When solenoid 2 is inside solenoid 1 and solenoid
1 has an AC current with I0 l 1A, N1 N2 100,
what is the voltage amplitude E0? Mantissa
first
Clicker question oct 28 (UNUSED malfunction)

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25
This blue metal object is moving to the right.
Only the central wire is inside the B field,
which points into the screen. What are the
directions of the current in the right and left
wires?
Clicker question, Oct 30, answer2
v
B x

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• -
• -

26
This blue metal object is moving to the right.
Only the central wire is inside the B field.
What is the direction of the force on the object?
Clicker question, Oct 30, answer2 again
v
B x

• -
• -
• -
• -

27
What is the energy stored in a 2 Henry inductor
carrying 2 amperes? (Abcissa)
Clicker question, Nov 4, answer4

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28
Which runner is leading in this race?
Clicker question, Nov 9, answer2
x
Prof. Plum
Miss Scarlett
t

• Prof. Plum
• Miss Scarlett

counter
29
A capacitor has C 200 mf 2x104 f. When a
voltage at frequency f 159 Hz is applied, what
is the reactance? Mantissa first
Clicker question, Nov 11 -- but not used, system
malfunctioned

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30
A rectangular box has area A and length L, energy
density is u, light energy crosses A in time t,
at velocity c L / t. What is the intensity of
the light (energy/area x time)?
Clicker question, Nov 16
L
A

• I u / c
• I u L A
• I u L / A
• I u c
• I u c t

31
A ray of light travels 10 m in air, then enters
water. It starts 4 m from the normal. How far
from the normal is it after traveling 10 m in
water?
Clicker question, Nov 20
4 m
ray
10 m
Air (n1)
Water (n1.3334/3)

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10 m
x?
32
A PH106 student wishes to listen to WPHY at 100.0
MHz. His radio tuner has an inductor with L 5
mH 0.005 H and a variable capacitor. He should
set the capacitor to have capacitance (in
farads), mantissa first
Clicker question, Nov 13 (20?) -- answer 5e8

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33
A PH106 student wishes to listen to Spike Radio
(WXYY) at 100.0 MHz. His radio tuner has an
inductor with L 5 mH 0.005 H and a variable
capacitor. He should set the capacitor to have
capacitance (in farads), Now exponent (remember
to ignore its sign)

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Solution
4 m
Use Snells Law n1 sin q1 n2 sin q2 1.0
4/10 4/3 x/10 x 4 / (4/3) 3 m
ray
10 m
Air (n1)
Water (n1.3334/3)
10 m
x?
35
An object is 6 cm in front of a concave mirror
of focal length 2 cm (radius 4 cm). What is the
image distance, in cm?
Clicker questions, Dec 2 -- these 4 questions
NOT used, data bad.

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36
Is the image ...

• In front of the mirror
• Behind the mirror

37
Is the image ...

• Real
• virtual

countdown
38
Is the image ...

• Rightside up
• Upside down

countdown