Physics – PHY101 Midterm Solved Past Papers

PHY101- Physics Midterm Solved Past Papers

Question No: 1 ( Marks: 1 ) – Please choose one
A net torque applied to a rigid object always tends to produce:
► rotational equilibrium
► linear acceleration
► angular acceleration
► rotational inertia

Question No: 2 ( Marks: 1 ) – Please choose one
An object attached to one end of a spring makes 20 vibrations in 10 s. Its
angular frequency is:
► 12.6 rad/s
► 1.57 rad/s
► 2.0 rad/s
► 6.3 rad/s
Question No: 3 ( Marks: 1 ) – Please choose one
In simple harmonic motion, the restoring force must be proportional to the:
► amplitude
► frequency
► velocity
► displacement

Question No: 4 ( Marks: 1 ) – Please choose one
Mercury is a convenient liquid to use in a barometer because:
► it is a metal
► it has a high boiling point
► it expands little with temperature
► it has a high density

Question No:5 ( Marks: 1 ) – Please choose one
The units of the electric field are:
► J/m
► J/(C·m)
► J/C
► J·C
Question No: 6 ( Marks: 1 ) – Please choose one
A farad is the same as a
► J/V
► V/J
► C/V
► V/C
Question No: 7 ( Marks: 1 ) – Please choose one
We desire to make an LC circuit that oscillates at 100 Hz using an
inductance of 2.5H. We also need a capacitance of:

► 1 F
► 1mF
► 1 μF
► 100 μF

Question No: 8 ( Marks: 1 ) – Please choose one
The wavelength of red light is 700 nm. Its frequency is_________________.
► 4.30 * 104 Hertz
► 4.30 * 103 Hertz
► 4.30 * 105 Hertz
► 4.30 * 102 Hertz

Question No: 9( Marks: 1 ) – Please choose one
Which of the following statements is NOT TRUE about electromagnetic
waves?
► Electromagnetic waves satisfy the Maswell’s Equation.
► Electromagnetic waves can not travel through space.
► The receptions of electromagnetic waves require an antenna.
► The electromagnetic radiation from a burning candle is unpolarized.

Question No: 10 ( Marks: 1 ) – Please choose one
Radio waves and light waves are ____________________________.
► Longitudinal waves
► Transverse waves
► Electromagnetic and transverse both
► Electromagnetic and longitudinal both

Question No: 11 ( Marks: 1 ) – Please choose one
Wien’s Law states that, lmax = ________ K.
► 2.90 * 10-3 Hertz
► 2.90 * 10-3 s
► 2.90 * 10-3 kg
► 2.90 * 10-3 m

Question No: 12 ( Marks: 1 ) – Please choose one
Interference of light is evidence that:
► the speed of light is very large
► light is a transverse wave
► light is a wave phenomenon
► light is electromagnetic in character

Question No: 13 ( Marks: 1 ) – Please choose one
Fahrenheit and Kelvin scales agree numerically at a reading of:
► -40
► 0
► 273
► 574

Question No: 14 ( Marks: 1 ) – Please choose one
According to the theory of relativity:
moving clocks run fast
► energy is not conserved in high speed collisions
► the speed of light must be measured relative to the ether
► none of the above are true

Question No: 15 ( Marks: 1 ) – Please choose one
Light from a stationary spaceship is observed, and then the spaceship moves
directly away from the observer at high speed while still emitting the light.
As a result, the light seen by the observer has:
► higher frequency and a longer wavelength than before
lower frequency and a shorter wavelength than before
► higher frequency and a shorter wavelength than before
► lower frequency and a longer wavelength than before

Question No: 16 ( Marks: 1 ) – Please choose one
How fast should you move away from a 6.0 × 1014 Hz light source to
observe waves with a frequency of 4.0 × 1014 Hz?
► 20c
► 38c
► 45c
► 51c

Question No: 17 ( Marks: 1 ) – Please choose one
The quantum number n is most closely associated with what property of the
electron in a hydrogen atom?
► Energy
► Orbital angular momentum
► Spin angular momentum
► Magnetic moment

Question No: 18 ( Marks: 1 ) – Please choose one
The quantum number ms is most closely associated with what property of the
electron in an atom?
► Magnitude of the orbital angular momentum
► Energy
► z component of the spin angular momentum
► z component of the orbital angular momentum

Question No: 19( Marks: 1 ) – Please choose one
As the wavelength of a wave in a uniform medium increases, its speed will
_____.
► Decrease
► Increase
Remain the same
► None of these

Question No: 20 ( Marks: 1 ) – Please choose one
The lowest tone produced by a certain organ comes from a 3.0-m pipe with
both ends open. If the speed of sound is 340m/s, the frequency of this tone is
approximately:

► A. 7Hz
► B. 14 Hz
► C. 28 Hz
► D. 57 Hz

Question No: 21 ( Marks: 1 ) – Please choose one
1. To raise the pitch of a certain piano string, the piano tuner:
► A. loosens the string
► B. tightens the string
► C. shortens the string
► D. lengthens the string

Question No: 22 ( Marks: 1 ) – Please choose one
An object attached to one end of a spring makes 20 vibrations in 10 s. Its
angular frequency is:
► 12.6 rad/s
► 1.57 rad/s
► 2.0 rad/s
► 6.3 rad/s

Question No: 23 ( Marks: 1 ) – Please choose one
For an object in equilibrium the net torque acting on it vanishes only if each
torque is calculated about:
► the center of mass

► the center of gravity
► the geometrical center
► the same point

Question No: 24 ( Marks: 1 ) – Please choose one
Ten seconds after an electric fan is turned on, the fan rotates at 300 rev/min.
Its average angular acceleration is:
► 3.14 rad/s2
► 30 rad/s2
► 30 rev/s2
► 50 rev/min2
► 1800 rev/s2

Question No: 25 ( Marks: 1 ) – Please choose one
A 4.0-N puck is traveling at 3.0m/s. It strikes a 8.0-N puck, which is
stationary. The two pucks stick together. Their common final speed is:
► 1.0m/s
► 1.5m/s
► 2.0m/s
► 2.3m/s

Question No:26 ( Marks: 1 ) – Please choose one
An object moving in a circle at constant speed:
► must have only one force acting on it
► is not accelerating
► is held to its path by centrifugal force
► has an acceleration of constant magnitude

Question No: 27 ( Marks: 1 ) – Please choose one
A plane traveling north at 200m/s turns and then travels south at 200m/s.
The change in its velocity is:
► 400m/s north
► 400m/s south
► zero
► 200m/s south

Question No: 28 ( Marks: 1 ) – Please choose one
At time t = 0 a car has a velocity of 16 m/s. It slows down with an
acceleration given by −0.50t, in m/s2 for t in seconds. It stops at t =
► 64 s
► 32 s
► 16 s
► 8.0 s

Question No: 29 ( Marks: 1 ) – Please choose one
1 mi is equivalent to 1609 m so 55 mph is:
► 15 m/s
► 25 m/s
► 66 m/s
► 88 m/s

Question No: 30( Marks: 1 ) – Please choose one

The number of significant figures in 0.00150 is:
► 5
► 4
► 3
► 2

Question No: 31 ( Marks: 1 ) – Please choose one
If the potential difference across a resistor is doubled:
► only the current is doubled
► only the current is halved
► only the resistance is doubled
► only the resistance is halved

Question No: 32 ( Marks: 1 ) – Please choose one

By using only two resistors, R1 and R2, a student is able to obtain
resistances of 3Ω, 4Ω, 12Ω, and 16 Ω. The values of R1 and R2 (in ohms)
are:
► 3, 4
► 2, 12
► 3, 16
► 4, 12

Question No: 33 ( Marks: 1 ) – Please choose one

Faraday’s law states that an induced emf is proportional to:
► the rate of change of the electric field
► the rate of change of the magnetic flux
► the rate of change of the electric flux
► the rate of change of the magnetic field

Question No: 34 ( Marks: 1 ) – Please choose one

A generator supplies 100V to the primary coil of a transformer. The primary
has 50 turns and the secondary has 500 turns. The secondary voltage is:
► 1000V
► 500V
► 250V
► 100V

Question No: 35 ( Marks: 1 ) – Please choose one

Which of the following electromagnetic radiations has photons with the
greatest energy?
► blue light
► yellow light
► x rays
► radio waves

Question No: 36 ( Marks: 1 ) – Please choose one

A virtual image is one:
► toward which light rays converge but do not pass through
► from which light rays diverge as they pass through
► toward which light rays converge and pass through
► from which light rays diverge but do not pass through

Question No: 37 ( Marks: 1 ) – Please choose one

What is the unit of magnification factor?
► meter.Kelvin
► radian.Kelvin
► degree.Kelvin
► no units

Question No: 38 ( Marks: 1 ) – Please choose one

During an adiabatic process an object does 100 J of work and its temperature
decreases by 5K. During another process it does 25 J of work and its
temperature decreases by 5 K. Its heat capacity for the second process is.
► 20 J/K
► 100 J/K
► 15 J/K
► 5 J/K

Question No: 39 ( Marks: 1 ) – Please choose one

An ideal gas expands into a vacuum in a rigid vessel. As a result there is:
► a change in entropy
► a decrease of internal energy
► an increase of pressure
► a change in temperature

Question No: 40 ( Marks: 1 ) – Please choose one

The Stern-Gerlach experiment makes use of:
► a strong uniform magnetic field
► a strong non-uniform magnetic field
► a strong uniform electric field
► a strong non-uniform electric field

Question No: 41 ( Marks: 3 )
Two people are carrying a uniform wooden board that is 3.00 m long and
weighs 160 N. If one person applies an upward force equal to 60 N at one
end, at what point does the other person lift? Begin with a free-body diagram
of the board.

Answer:
Forces in x direction = 0
Forces in Y = F1 + F2 – W
Given:
L = 3.00 m F1 = 60 N
W = 160 N F2 = ? and x2 = ?
Sum of forces and torques = 0
Sum Force = F1 + F2 – W = 0
60N + F2 – 160 N = 0
F2 = 100 N
My pivot point is at F2.
Sum of torques = 0
Torque F1 = F1(L – x2)
Torque F2 = 0 b/c at pivot point
Torque W = W(L/2 – x2)
F1L – F1x2 + (WL)/2 – Wx2 = 0
(60)(3) – 60×2 + (160 * 3)/2 – 160×2 = 0
180-60×2 + 240-160×2 = 0
420-220×2 = 0
x2 = 1.9m

Question No: 42 ( Marks: 5 )
A bike accelerates uniformly from rest to a speed of 7.10 m/s over a distance
of 35.4 m. Determine the acceleration of the bike.

Answer:
2as = vf2 – vi2
2a(35.4) = (7.10)2 – (0)2
2a(35.4) = 50.41
A = .71 m/s2

Question No: 42 ( Marks: 5 )
A flat loop of wire consisting of a single turn of cross-sectional area 8.00
cm2 is perpendicular to a magnetic field that increases uniformly in
magnitude from 0.500 T to 2.50 T in 1.00 s. What is the resulting induced
current if the loop has a resistance of 2.00 W?

Answer:
E=(Bf-Bi)*A/t=(2.5-0.5)*8*10-4/1=1.6*10-3 V
I=E/R=1.23 mA