A body is moving parallel to the z-axes. Its velocity is constant and equal to 12 m/s. Which vector of velocity is possible:
No correct answer
The velocity of the body is . What is the position vector for this body (in general form)?
No correct answer
Velocity of a body depends on time by the following form . What is the unit of the coefficient [B]?
No correct answer
The SI unit of density is?
[kg/m3]
[kg/cm3]
[g/m3]
[1/m3]
No correct answer
Every action or force upon an object must have an equal and ____________ reaction.
Measurable
Complete
Opposite
Correct
No correct answer
A baseball of mass m is thrown upward with some initial speed. A gravitational force is exerted on the ball
At all points in its motion
At all points in its motion except at the highest point
At no points in its motion
Only at downward part of its direction
No correct answer
The kinetic friction will always be
Greater than static friction
Equal to the static friction
Less than static friction
Negative
No correct answer
The unit of coefficient of friction in SI system is
Newton
Dyne
None of these
No unit
No correct answer
Whenever a constant force is applied on a body then it will move with __________.
Constant Speed
Constant Velocity
Constant Acceleration
None of them
No correct answer
Powerisa __________.
Scalar Quantity
Vector Quantity
None of these
Rate of force
No correct answer
The dot product of force and velocity is called __________.
Work
Power
Energy
Momentum
impulse
When the force and displacement are perpendicular to each other, then work is __________.
zero
Maximum
None of these
Depends on force magnitude
No correct answer
Centripetal acceleration and tangential acceleration are always __________.
Parallel to Each other, but in opposite direction
Perpendicular to each other
None of these
Parallel to each other, but in the same direction
Equal to each other
The dimensions of angular momentum are __________.
MLT-1
MLT-3
MLT-2
ML2T-2
ML2T-1
The moment of inertia of a wheel about its axle does not depend upon its:
Diameter
Mass
distribution of mass
speed of rotation
radius
Two waves have the same frequency. Which wave characteristic must also be identical for both waves?
Phase
Amplitude
All charateristics
Intensity
Period
A mechanical wave generally does NOT
move the medium from one place to another
move through a medium
move through solids
disturb the medium
have a interference effect
The moment of inertia of a body depends on
the angular velocity
the angular acceleration
the mass distribution
the torque acting on the body
direction of rotation
A skater can spin faster by pulling in her arms closer to her body or spin slower by spreading her arms out from her body. This is due to
Conservation of momentum
Newtons second law
Conservation of energy
Newtons third law
Conservation of angular momentum
The SI units for Coulomb constant keare:
N·m2/C2
N·m/C
N·m/C2
m2/C2
No correct answer
The electric field vector E can be expressed as:
E=Fe/q
E=Fe/q2
E=Fe·q
E=Fe·q2
No correct answer
If the electric field is uniform and makes an angle θ with the normal to a surface of area A, the electric flux through the surface is:
EAcosθ
EAsinθ
Acosθsinθ
Ecosθ
No correct answer
Gausss law says that the net electric flux through any closed gaussian surface is equal to:
qin/ε0
qin·ε0
ε0/qin
qinqout/ε0
No correct answer
The potential difference between two points A and B in a uniform electric field E, where s (d=|s|) is a vector that points from A to B and is parallel to E is:
∆V=-Ed
∆V=0
∆V=Ed
∆V=-Edsinθ
No correct answer
The SI unit of capacitance is:
C/V
V/C
C/V2
C/V·m
No correct answer
The equivalent capacitance of a parallel combination of capacitors is:
Ceq=C1+C2+C3+...
1/Ceq=1/C1+1/C2+1/C3+...
Ceq=C1=C2=C3=...
Ceq=C1·C2·C3·...
No correct answer
If two or more capacitors are connected in series, the equivalent capacitance of the series combination is given by:
Ceq=C1+C2+C3+...
1/Ceq=1/C1+1/C2+1/C3+...
Ceq=C1=C2=C3=...
Ceq=C1·C2·C3·...
No correct answer
The average current in a conductor is related to the motion of the charge carriers through the relationship:
Iav=nqvdA
Iav=nqvd
Iav=qvdA
Iav=nq/vdA
No correct answer
Ohms law in the differential form is:
J=σE
I=U/R
I=R/U
J=σ/E
No correct answer
Ohms law in the integral form is:
J=σE
I=U/R
I=R/U
J=σ/E
No correct answer
For a uniform block of material of cross sectional area A and length l, the resistance over the length l is:
R=ρl/A
R=l/A
R=A/l
R=lA
No correct answer
The power supplied to the element, is:
P=I∆V
P=I/∆V
P=I2∆V
P=I∆V2
No correct answer
The power delivered to a resistor can be defined as:
P=I2R
P=IR
P=IR2
P=I2/R
No correct answer
The equivalent resistance of a set of resistors connected in series is:
Req=R1+R2+R3+...
1/Req=1/R1+1/R2+1/R3+...
Req=1/(R1+R2+R3+...)
Req=R1+R2+R3+...
No correct answer
The equivalent resistance of a set of resistors connected in parallel is found from the relationship:
Req=R1+R2+R3+...
1/Req=1/R1+1/R2+1/R3+...
Req=1/(R1+R2+R3+...)
Req=R1+R2+R3+...
No correct answer
Two objects, with different sizes, masses, and temperatures, are placed in thermal contact. Energy travels
From the larger object to the smaller object
From the object with more mass to the one with less
From the object at higher temperature to the object at lower temperature
Energy doesnt travel
From the object at lower temperature to the object at higher temperature
On a day when the temperature reaches 50°F, what is the temperature in degrees Celsius and in kelvins?
500 C, 323 K,
400 C, 313 K,
300 C, 303 K,
200 C, 293 K,
100 C, 283 K.
The first law of thermodynamics can be given as ________.
for any spontaneous process, the entropy of the universe increases
the entropy of a pure crystalline substance at absolute zero is zero
ΔS = Q/T at constant temperature
ΔE = Q + W
if two systems are in thermal equilibrium with a third system, they are also in thermal equilibrium with each other
The second law of thermodynamics can be given as __________
for any spontaneous process, the entropy of the universe increases
the entropy of a pure crystalline substance at absolute zero is zero
ΔS = Q/T at constant temperature
if two systems are in thermal equilibrium with a third system, they are also in thermal equilibrium with each other
ΔE = Q + W
Which of the following is not a state function?
Pressure
Volume
Temperature
Mole
Energy
Two containers hold an ideal gas at the same temperature and pressure. Both containers hold the same type of gas but container B has twice the volume of container A. The average translational kinetic energy per molecule in container B is
twice that for container A
the same as that for container A
half that for container A
impossible to determine
twice or half that for container A, depends on the materialcontainers
Two containers hold an ideal gas at the same temperature and pressure. Both containers hold the same type of gas but container B has twice the volume of container A. The internal energy of the gas in container B is
twice that for container A
the same as that for container A
half that for container A
twice or half that for container A, depends on the materialcontainers
impossible to determine
Two containers hold an ideal gas at the same temperature and pressure. Both containers hold the same type of gas but container B has twice the volume of container A. The rms speed of the gas molecules in container B is
twice that for container A
the same as that for container A
half that for container A
twice or half that for container A, depends on the materialcontainers
impossible to determine
How does the internal energy of an ideal gas change as it follows path in figure?
increases
decreases
stays the same
There is not enough information to determine how changes
In isothermal process there isnt internal energy
How does the internal energy of an ideal gas as it follows path along the isotherm labeled in figure?
increases
decreases
stays the same
There is not enough information to determine how changes
In isothermal process there isnt internal energy
Latent heat is
the heat released or absorbed by a thermodynamic system during a process that occurs without a change in temperature
the amount of energy needed to raise the temperature of sample by 1°C
the heat capacity per unit mass
the amount of heat required to change a unit mass of a substance by one degree in temperature
amount of energy necessary to raise the temperature of 1 g of water from 14.5°C to 15.5°C.
Adiabaticprocess is
process that occurs at constant volume
process that occurs at constant temperature
process that occurs at constant pressure
process in which the net heat transfer between the system and its surroundings is zero
process that obeys the relation: pVn=C
A diatomic gas molecule has ... degrees of freedom
3
5
6
7
7 and more
Energymaybetransferredby
work
conduction
convection
radiation
all answers are correct
The molar specific heat of a gas is measured at constant volume and found to be 11R/2. The gas is most likely to be
monatomic
diatomic
monatomic or diatomic, depends on the conditions
polyatomic
all answers are incorrect
Parallel wires carrying currents I1 and I2 respectively
repel if they are directed opposite
will attract if they are directed opposite
will not interact
will always repel, no matter which direction they have
will always attract, no matter which direction they have
What are the opposite ends of a magnet called?
Its terminals
Its north and south poles
Its magnetic fields
Its electromagnetic poles
Negative and positive poles
How are electrical charges and magnetic poles similar?
Unlike attract and the same type repel
Both are plus and minus
Magnetic poles attract electrons
Both change positive to negative charges
No correct answer
How can you show that electricity creates a magnetic field?
Use a compass near a wire with current flowing through it
Only magnets create magnetic fields
Move a wire through a magnetic field
Electricity does not create a magnetic field
Connect a battery to the magnetic field
How can you make an electromagnet?
Attach a natural magnet to a battery
Run current through a wire wrapped around an iron rod
Line up the N and S poles of a magnet with an electric wire
Wrap a magnet around a piece of wire with current flowing through it
No correct answer
What happens when you turn off the current in an electromagnet?
The magnetism is turned off
The current keeps flowing because of the magnetic force
The electromagnet reverses its polarity
The electromagnet becomes a generator
Nothing happens
How can you create electricity with a magnet?
Attach a magnet to a battery
By putting a current through a wire around a magnet
By moving a wire through a magnetic field
You can't, because only friction on electric charges creates electricity
No correct answer
Can you create electricity with a magnet?
No, because only friction on electric charges or batteries create electricity
Yes, by moving a wire through a magnetic field
Yes, by putting a current through a wire around a magnet
Yes because magnets use electricity to stay effective
It is impossible
The geomagnetic field
makes the Earth like a huge horseshoe magnet
runs exactly through the geographic poles
makes a compass work
makes an electromagnet work
makes all material electromagnet
A material that can be permanently magnetized is generally said to be
Magnetic
dielectric
electromagnetic
permanently magnetic
ferromagnetic
The magnetic flux around a straight current-carrying wire
gets stronger with increasing distance from the wire
is strongest near the wire
does not vary in strength with distance from the wire
consists of straight lines parallel to the wire
depends only on current direction
The gauss is a unit of
overall magnetic field strength
electric field strength
ampere-turns
magnetic flux density
magnetic power
If a wire coil has 10 turns and carries 500 mA of current, what is the magnetomotive force in ampere-turns?
5,000
50
0.5
5.0
0.02
Which of the following is not generally observed in a geomagnetic storm?
Charged particles streaming out from the Sun
All of them is not observed
Fluctuations in the Earths magnetic field
Disruption of electrical power transmission
Disruption of microwave propagation
A device that reverses magnetic field polarity to keep a dc motor rotating is
a solenoid
a galvanometer
an armature coil
a commutator
a field coil
When the speed at which a conductor is moved through a magnetic field is increased, the induced voltage
increases
decreases
remains constant
reaches zero
increases and then decreases
The induced voltage across a coil with 250 turns that is located in a magnetic field that is changing at a rate of 8 Wb/s is
1,000 V
2,000 V
31.25 V
312.5V
3.125 V
For a given wirewound core, an increase in current through the coil
reverses the flux lines
decreases the flux density
increases the flux density
causes no change in flux density
decreases the density by factor of 2
If the cross-sectional area of a magnetic field increases, but the flux remains the same, the flux density
Increases
decreases
remains the same
doubles
increases and then decreases
When the current through the coil of an electromagnet reverses,
direction of the magnetic field reverses
direction of the magnetic field remains unchanged
magnetic field expands
magnetic field collapses
magnetic field doubles
What is the reluctance of a material that has a length of 0.07 m, a cross-sectional area of 0.014 m2, and a permeability of 4,500Wb/At × m?
1111 At/Wb
111 At/Wb
11 At/Wb
1 At/Wb
0.1 At/Wb
A coil of wire is placed in a changing magnetic field. If the number of turns in the coil is decreased, the voltage induced across the coil will
increase
decrease
remain constant
be excessive
increases and then decreases
What is the flux density when the flux is 5.5 Wb and the cross-sectional area is 6 × 103 m2?
91.7 µT
917 µT
91 T
9.7 T
0.9T
If the steel disk in a crankshaft position sensor has stopped with the tab in the magnet's air gap, the induced voltage
increases
decreases
is zero
will remain constant
increases and then decreases
What is the flux density in a magnetic field in which the flux in 0.1 m2 is 600 µWb?
6,000 µT
600 µT
600 T
6 T
0.6T
What is the charge carrier in semiconductors?
Holes
Electrons
Ions
Holes and ions
Holes and electrons
p type semiconductor means
majority charge carrier is electrons
majority charge carrier is holes
majority charge carrier is ions
majority charge carriers are electrons and holes
conduct no current at all
n type semiconductor means
majority charge carrier is electrons
majority charge carrier is holes
majority charge carrier is ions
majority charge carriers are electrons and holes
conduct no current at all
Show the SI unit of magnetic field B:
T
Wb
A/m
A
V
Basicsourceofmagnetism ______________.
Charged particles alone
Movement of charged particles
Magnetic dipoles
Magnetic and electric domains
No correct answer
Show the SI unit of magnetic flux:
T
Wb
A/m
A
V
Which of the following statements is correct?
Earth's north pole is magnetic north
The north pole of a magnet points towards the Earth's north pole.
Like poles of a magnet attract each other and unlike poles repel.
The SI unit of the magnetic field is the gauss
No correct answer
Three particles travel through a region of space where the magnetic field is out of the page, as shown in Figure. The electric charge of each of the three particles is, respectively,
1 is neutral, 2 is negative, and 3 is positive
1 is negative, 2 is neutral, and 3 is positive
1 is positive, 2 is negative, and 3 is neutral
1 is positive, 2 is neutral, and 3 is negative
No correct answer
What is the inductive reactance of a 20-mH inductor at a frequency of 60 Hz?
7.5 m
0.13
7.5
12E-1
No correct answer
The figure shows a simple AC circuit composed of a capacitor connected across the terminals of an ac generator. If the frequency of the generator is doubled, what happens to the capacitive reactance of the capacitor?
It decreases by a factor of 2
It increases by a factor of 2
It increases by a factor of 4
It decreases by a factor of 4
No correct answer
An electron moves in the plane of this paper toward the top of the page. A magnetic field is also in the plane of the page and directed toward the right. The direction of the magnetic force on the electron is
toward the left edge of the page
toward the right edge of the page
upward out of the page
downward into the page.
When there is no current in the wire, it remains vertical.
A wire suspended vertically between the poles of a magnet. The setup shown in the figure as seen looking at the south pole of the magnet, so that the magnetic field (blue crosses) is directed into the page. If current is downward, show the suitable deflection of wire:
Not enough information to determine
None of them
Consider the current in the length of wire shown in figure. Where the magnetic field is greatest?
A
B
C
Everywhere is the same
Consider the magnitudes of for the closed paths in the figure.Where the magnitude of is the greatest?
a
b
c
d
a and b
What charge is located in the figure?
Negative
Positive
Uncharged
Positive and negative
Not possible to determine
Show the unit of electric field (E) in SI system?
C
V
V/m
C/m3
C/m2
Show the unit of electric potential in SI system?
C
V
V/m
C/m2
C/m3
If charge is increased by factor of 2, how does its electric potential change?