PHY101 Past Solved MCQS and Quiz Mega File

www.vudesk.com

FINALTERM  EXAMINATION

Spring 2009

PHY101- Physics (Session - 2)

Question No: 1    ( Marks: 1 )    - Please choose one

  The number of significant figures in 0.00150 is:

       ► 5

       ► 4

       ► 3

       ► 2

   

Question No: 2    ( Marks: 1 )    - Please choose one

 One revolution is the same as:

2π rad

       ► 1 rad

       ► 57 rad

       ► π/2 rad

       ► π rad

       ► 2π rad

   

Question No: 3    ( Marks: 1 )    - Please choose one

 For a body to be in equilibrium under the combined action of several forces:

       ► all the forces must be applied at the same point

all the forces must be applied at the same point

       ►  all of the forces form pairs of equal and opposite forces

       ► any two of these forces must be balanced by a third force

       ► the sum of the torques about any point must equal zero

   

Question No: 4    ( Marks: 1 )    - Please choose one

 A bucket of water is pushed from left to right with increasing speed across a horizontal surface.

Consider the pressure at two points at the same level in the water.

       ►  It is the same

       ► It is higher at the point on the left

       ► It is higher at the point on the right

       ► At first it is higher at the point on the left but as the bucket speeds up it is lower there

   

Question No: 5    ( Marks: 1 )    - Please choose one

 An organ pipe with both ends open is 0.85m long. Assuming that the speed of sound is 340m/s, the frequency of the third harmonic of this pipe is:

       ► A. 200 Hz

       ► B. 300 Hz

       ► C. 400 Hz

       ► D. 600 Hz

   

Question No: 6    ( Marks: 1 )    - Please choose one

 Capacitors C1 and C2 are connected in series. The equivalent capacitance is given by

       ► C₁C₂/(C₁ + C₂)

       ► (C₁ + C₂)/C₁C₂

       ► 1/(C₁ + C₂)

       ► C₁/C₂

   

Question No: 7    ( 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: 8    ( Marks: 1 )    - Please choose one

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

       ► 3, 4

       ► 2, 12

       ► 3, 16

       ► 4, 12

   

Question No: 9    ( 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: 10    ( 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: 11    ( 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: 12    ( Marks: 1 )    - Please choose one

 In some movies, you sometimes see an actor looking in a mirror and you can see his face in the mirror. During the filming of this scene, what does the actor see in the mirror?

       ► His face

       ► Your face

       ► The movie camera

       ► The director's face

   

Question No: 13    ( Marks: 1 )    - Please choose one

 A laser in a compact disc player generates light that has a wavelength of 780 nm in air. The light then enters into the plastic of a CD. If the index of refraction of plastic is 1.55, the speed of this light once enter the plastic is ________.

       ► 3.00 * 10⁸ m/s

       ► 1.94 * 10⁸ m/s

       ► 4.29 * 10⁸ km/h

       ► 3.00 * 10⁸ km/h

   

Question No: 14    ( 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: 15    ( 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: 16    ( Marks: 1 )    - Please choose one

 What is the unit of magnification factor?

       ► meter.Kelvin

       ► radian.Kelvin

       ► degree.Kelvin

       ► no units

   

Question No: 17    ( 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: 18    ( 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: 19    ( 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: 20    ( Marks: 1 )    - Please choose one

 A large collection of nuclei are undergoing alpha decay. The rate of decay at any instant is proportional to:

       ► the number of undecayed nuclei present at that instant

       ► the time since the decays started

       ► the time remaining before all have decayed

       ► the half-life of the decay

   

Question No: 21    ( Marks: 1 )

 Which weighs more, a liter of ice or a liter of water?

   

Question No: 22    ( Marks: 1 )

 Will the current in a light bulb connected to a 220-V source be greater or less than when the same bulb is connected to 110-V source?

   

Question No: 23    ( Marks: 1 )

 How is the wavelength of light related to its frequency?

   

Question No: 24    ( Marks: 1 )

 We don't notice the de Broglie wavelength for a pitched baseball. Is this because

the wavelength is very large or because it is very small?

   

Question No: 25    ( Marks: 2 )

 Does every magnet necessarily have a north and south pole? Explain

Question No: 26    ( Marks: 2 )

 In a cool room, a metal or marble table top feels much colder to the touch than does a wood surface even though they are at the same temperature. Why?

   

Question No: 27    ( Marks: 3 )

 If a water wave oscillates up and down three times each second and the distance between wave crests is 2 m, what is its frequency? What is its wavelength? What is its wave speed?

   

Question No: 28    ( Marks: 3 )

 A transformer has N₁= 350 turns and N₂ = 2 000 turns. If the input voltage is D

v(t) = (170 V) cos w  t, what rms voltage is developed across the secondary coil?

   

Question No: 29    ( Marks: 3 )

 Why do astronomers looking at distant galaxies talk about looking backward in time?

   

Question No: 30    ( Marks: 3 )

 Some distant astronomical objects, called quasars, are receding from us at half the speed of light (or greater). What is the speed of the light we receive from these quasars?

   

Question No: 31    ( Marks: 5 )

 Consider a lamp hanging from a chain. What is the tension in the chain?

  

Question No: 32    ( Marks: 5 )

 A proton travels with a speed of 3.00 * 10⁶ m/s at an angle of 37.0° with the direction of a magnetic field of 0.300 T in the + y direction. What are (a) the magnitude of the magnetic force on the proton and (b) its acceleration?

   

Question No: 33    ( Marks: 5 )

 1. Light from the Sun takes approximately 8.3 min to reach the Earth. During this time interval the Earth has continued to rotate on its axis. How far is the actual direction of the Sun from its image in the sky?

2. Do all current-carrying conductors emit electromagnetic waves? Explain

2. Yes all current carrying conductors emit electromagnetic waves, and these are at the right angle of the current passes thorough as right hand rule of Fleming’s explains it.

   

Question No: 34    ( Marks: 5 )

 Explain solar convection zone. What is its other name?

   

Question No: 35    ( Marks: 10 )

 a) Explain why you can't just open your refrigerator to cool your kitchen on a hot day. Why is it that turning on a room air conditioner will cool down the room but opening a refrigerator door will not?

b) On a humid day, water vapor condenses on a cold surface. During condensation, the entropy of the water(a) in-creases, (b) remains constant, (c) decreases, (d) may decreases or remain unchanged. Give its reason.

Question No: 1    ( Marks: 1 )    - Please choose one

 As a 2.0-kg block travels around a 0.50-m radius circle it has an angular speed of 12 rad/s. The circle is parallel to the xy plane and is centered on the z axis, a distance of 0.75m from the origin. The z component of the angular momentum around the origin is:

       ► 6.0kg · m2/s

► 6.0kg · m2/s

       ► 9.0kg · m2/s

       ► 11 kg · m2/s

       ► 14 kg · m2/s

   

Question No: 2    ( Marks: 1 )    - Please choose one

 A net torque applied to a rigid object always tends to produce:

       ► rotational equilibrium

       ►  linear acceleration

       ► rotational equilibrium

       ► angular acceleration

       ►  rotational inertia

   

Question No: 3    ( Marks: 1 )    - Please choose one

 An object attached to one end of a spring makes 20 vibrations in 10 s. Its angular frequency is:

      ► 2.0 rad/s

 ► 12.6 rad/s

       ► 1.57 rad/s

       ► 2.0 rad/s

       ► 6.3 rad/s

   

Question No: 4    ( Marks: 1 )    - Please choose one

 In simple harmonic motion, the restoring force must be proportional to the:

       ► displacement

       ► amplitude

       ► frequency

       ► velocity

       ► displacement

    

Question No: 5    ( Marks: 1 )    - Please choose one

 Mercury is a convenient liquid to use in a barometer because:

       ►  it has a high density

       ► it is a metal

       ► it has a high boiling point

       ► it expands little with temperature

       ►  it has a high density

   

Question No: 6    ( Marks: 1 )    - Please choose one

 The units of the electric field are:

► J/m

       ► J/m

       ► J/(C·m)

       ► J/C

       ► J·C

   

Question No: 7    ( Marks: 1 )    - Please choose one

 A farad is the same as a

     ► J/V

  ► J/V

       ► V/J

       ► C/V

       ► V/C

   

Question No: 8    ( 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:

       ► 100 μF

       ► 1 F

       ► 1mF

       ► 1 μF

       ► 100 μF

   

Question No: 9    ( Marks: 1 )    - Please choose one

 The wavelength of red light is 700 nm. Its frequency is ____________________.

       ► 4.30 * 10⁵Hertz

       ► 4.30 * 10⁴ Hertz

       ► 4.30 * 10³ Hertz

       ► 4.30 * 10⁵Hertz

       ► 4.30 * 10² Hertz

   

Question No: 10    ( Marks: 1 )    - Please choose one

 Which of the following statements is NOT TRUE about electromagnetic waves?

       ► The electromagnetic radiation from a burning candle is unpolarized.

       ► 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: 11    ( Marks: 1 )    - Please choose one

 Radio waves and light waves are ____________________________.

► Electromagnetic and transverse both

       ► Longitudinal waves

       ► Transverse waves

       ► Electromagnetic and transverse both

       ► Electromagnetic and longitudinal both

   

Question No: 12    ( Marks: 1 )    - Please choose one

 Wien's Law states that, _lmax = ________ K.

       ► 2.90 * 10^-3m

       ► 2.90 * 10^-3 Hertz

       ► 2.90 * 10^-3 s

       ► 2.90 * 10^-3 kg

       ► 2.90 * 10^-3m

   

Question No: 13    ( Marks: 1 )    - Please choose one

  Interference of light is evidence that:

       ► light is a wave phenomenon

       ► the speed of light is very large

       ► light is a transverse wave

       ► light is a wave phenomenon

       ► light is electromagnetic in character

   

Question No: 14    ( Marks: 1 )    - Please choose one

 Fahrenheit and Kelvin scales agree numerically at a reading of:

       ► -40

       ► -40

       ► 0

       ► 273

       ► 574

   

Question No: 15    ( Marks: 1 )    - Please choose one

 According to the theory of relativity:

       ► moving clocks run fast

       ► 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: 16    ( 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:

       ► lower frequency and a shorter wavelength than before

       ► 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: 17    ( 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?

       ► 38c

       ► 20c

       ► 38c

       ► 45c

       ► 51c

   

Question No: 18    ( Marks: 1 )    - Please choose one

 The quantum number n is most closely associated with what property of the electron in a hydrogen atom?

       ► Energy

       ► Energy

       ► Orbital angular momentum

       ► Spin angular momentum

       ► Magnetic moment

   

Question No: 19    ( Marks: 1 )    - Please choose one

 The quantum number m_s is most closely associated with what property of the electron in an atom?

              ► Energy

► Magnitude of the orbital angular momentum

       ► Energy

       ► z component of the spin angular momentum

       ► z component of the orbital angular momentum

   

Question No: 20    ( Marks: 1 )    - Please choose one

 As the wavelength of a wave in a uniform medium increases, its speed will _____.

      ► Remain the same

       ► Decrease

       ► Increase

       ► Remain the same

       ► None of these

   

Question No: 21    ( 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.

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) - 60x2 + (160 * 3)/2 - 160x2 = 0
180-60x2 + 240-160x2 = 0
420-220x2 = 0
x2 = 1.9m

   

Question No: 22    ( Marks: 3 )

 If a charged particle moves in a straight line through some region of space, can you say that the magnetic field in that region is zero?

   

Question No: 23    ( Marks: 3 )

 You want to explore the shape of a cel1ain molecule by scattering electrons of momentum p from a gas of the molecules and studying the deflection of the electrons. You will be able to see finer details in the molecules by (a) increasing p; (b) decreasing p: (c) not worrying what p is.

   

Question No: 24    ( Marks: 3 )

 A vessel is filled with gas at some equilibrium pressure and temperature. Can all gas molecules in the vessel have the same speed?

   

Question No: 25    ( Marks: 3 )

 What are the properties of wave  function?

Wave functions contain all the measurable information about the particles

Wave functions are continuous.

They allow energy calculations via schrodinger equation.

They establish the probability distribution in three dimensions.

They permit calculation of most probable values of given variables.

   

Question No: 26    ( 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.

2as = vf² – vi²

2a(35.4) = (7.10)² – (0)²   

2a(35.4) = 50.41

A = .71 m/s²

Question No: 27    ( 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?

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

Question No: 28    ( Marks: 5 )

 An ideal gas is contained in a vessel at 300 K. If the temperature is increased to 900 K, by what factor does each one of the following change? (a) The average kinetic energy of the molecules. (b) The rms molecular speed. (c) The average momentum change of one molecule in a collision with a wall. (d) The rate of collisions of molecules with walls. (e) The pressure of the gas.

   

Question No: 29    ( Marks: 5 )

 Who discover the nucleus? Write the experimental setup that he follows.

Ans:

Lord Rutherford discovered the nucleus. He carried out his famous experiment that showed the existence of a small but very heavy core of the atom. He arranged for a beam of alpha particles to strike gold atoms in a thin foil of gold. If the positive and negative charges in the atom were randomly distributed, all ' would go through without any deflection. But a lot of backscattering was seen, and some alphas were even deflected back in the direction of the incident beam. This was possible only if they were colliding with a very heavy object inside the atom.

   

Question No: 30    ( Marks: 5 )

 In an analogy between electric current and automobile traffic flow, what would correspond to charge? What would correspond to current?

   

Question No: 31    ( Marks: 10 )

(a) When can you expect a body to emit blackbody radiation?

 (b) Which law is obeyed by Sun and other stars, briefly explain it.

(a)  When can you expect a body to emit blackbody radiation?

Ans:

Waves are emitted when charges accelerate. Blackbody radiation occurs for exactly this reason as well. If a body is heated up, the electrons, atoms, and molecules which it contains undergo violent random motion. Light may emit by electrons in one atom and absorbed in another. Even an empty box will be filled with blackbody radiation because the sides of the box are made up of material that has charged constituents that radiate energy when they undergo acceleration during their random motion. A blackbody is both an ideal absorber and an ideal radiator. At high temperature, a body emits radiation of shorter wavelength. Temperature is inversely proportional to wavelength.

(b)  Which law is obeyed by Sun and other stars, briefly explain it.

Ans:

The Sun and other stars obey Wien's Law since the gases they are composed of emit radiation that is in equilibrium with the other materials. Wien's law allows astronomers to determine the temperature of a star because the wavelength at which a star is brightest is related to its temperature.

Question # 1 of 10 ( Start time: 03:57:12 PM ) Total Marks: 1
The speed of a sound wave is determined by:
Select correct option:

its amplitude
its intensity
the transmitting medium
number of harmonics present
Question # 2 of 10 ( Start time: 03:58:13 PM ) Total Marks: 1
Take the speed of sound to be 340m/s. A thunder clap is heard about 3 s after the lightning is seen. The source of both light and sound is:
Select correct option:

moving overhead faster than the speed of sound
emitting a much higher frequency than is heard
emitting a much lower frequency than is heard
about 1000m away
Question # 3 of 10 ( Start time: 03:59:37 PM ) Total Marks: 1
If the speed of sound is 340m/s a plane flying at 400m/s creates a conical shock wave with an apex half angle of:
Select correct option:

0 (no shock wave)
32?
40?
58?
Question # 4 of 10 ( Start time: 04:01:00 PM ) Total Marks: 1
Two sound waves are traveling through a container of unknown gas. Wave A has a wavelength of 1.2 m. Wave B has a wavelength of 3.6 m. The frequency of wave B must be __________ the frequency of wave A.
Select correct option:

One-ninth
One-third
The same as
Three times larger than
Question # 6 of 10 ( Start time: 04:03:07 PM ) Total Marks: 1
Two sound waves are traveling through a container of unknown gas. Wave A has a wavelength of 1.2 m. Wave B has a wavelength of 3.6 m. The velocity of wave B must be __________ the velocity of wave A.
Select correct option:

One-ninth
One-third
The same as
Three times larger than
Question # 7 of 10 ( Start time: 04:04:27 PM ) Total Marks: 1
The speed of a wave depends upon (i.e., is causally affected by)...
Select correct option:

The properties of the medium through which the wave travels
The wavelength of the wave.
The frequency of the wave.
Both the wavelength and the frequency of the wave.
Question # 8 of 10 ( Start time: 04:05:35 PM ) Total Marks: 1
A plane produces a sonic boom only when:
Select correct option:

it emits sound waves of very long wavelength
it emits sound waves of high frequency
it flys at high altitudes
it flys faster than the speed of sound

Question # 9 of 10 ( Start time: 04:06:18 PM ) Total Marks: 1
An object attached to one end of a spring makes 20 complete oscillations in 10 s. Its period is:
Select correct option:

2Hz
0.5 s
0.5Hz
2 s

Question # 10 of 10 ( Start time: 04:07:33 PM ) Total Marks: 1
In simple harmonic motion, the restoring force must be proportional to the:
Select correct option:

amplitude
frequency
velocity
displacement

Question # 1 of 10 ( Start time: 04:09:33 PM ) Total Marks: 1
The speed of a wave depends upon (i.e., is causally affected by)...
Select correct option:

The properties of the medium through which the wave travels
The wavelength of the wave.
The frequency of the wave.
Both the wavelength and the frequency of the wave.

Question # 2 of 10 ( Start time: 04:10:21 PM ) Total Marks: 1
A transverse wave is transporting energy from east to west. The particles of the medium will move_____.
Select correct option:

East to west only
Both eastward and westward
North to south only
Both northward and southward


Question # 3 of 10 ( Start time: 04:11:46 PM ) Total Marks: 1
A force of 5000N is applied outwardly to each end of a 5.0-m long rod with a radius of 34.0 cm and a Young’s modulus of 125 × 108 N/m2. The elongation of the rod is:
Select correct option:

0.0040mm
0.14mm
0.55mm
1.42mm
Question # 4 of 10 ( Start time: 04:12:51 PM ) Total Marks: 1
Take the speed of sound to be 340m/s. A thunder clap is heard about 3 s after the lightning is seen. The source of both light and sound is:
Select correct option:
moving overhead faster than the speed of sound
emitting a much higher frequency than is heard
emitting a much lower frequency than is heard
about 1000m away

Question # 5 of 10 ( Start time: 04:13:42 PM ) Total Marks: 1
As the wavelength of a wave in a uniform medium increases, its frequency will _____.
Select correct option:

Decrease
Increase
Remain the same
None of these
Question # 6 of 10 ( Start time: 04:14:11 PM ) Total Marks: 1
Sound and light waves both
Select correct option:

have similar wavelength
obey the laws of reflection
travel as longitudinal waves
travel through vacuum
Question # 7 of 10 ( Start time: 04:15:03 PM ) Total Marks: 1
A force of 5000N is applied outwardly to each end of a 5.0-m long rod with a radius of 34.0 cm and a Young's modulus of 125 × 108 N/m2. The elongation of the rod is:
Select correct option:

0.0020mm
0.0040mm
0.14mm
0.55mm

Question # 8 of 10 ( Start time: 04:16:04 PM ) Total Marks: 1
A mosquito's buzz is often rated with a decibel rating of 40 dB. Normal conversation is often rated at 60 dB. How many times more intense is normal conversation compared to a mosquito's buzz?
Select correct option:

2
20
100
400

Question # 1 of 10 ( Start time: 07:18:05 PM ) Total Marks: 1
In simple harmonic motion, the restoring force must be proportional to the:
Select correct option:

amplitude
frequency
velocity
displacement


Question # 2 of 10 ( Start time: 07:18:35 PM ) Total Marks: 1
As the wavelength of a wave in a uniform medium increases, its speed will _____.
Select correct option:

Decrease
Increase
Remain the same
None of these

Question # 3 of 10 ( Start time: 07:19:16 PM ) Total Marks: 1
Young’s modulus is a proportionality constant that relates the force per unit area applied perpendicularly at the surface of an object to:
Select correct option:

the shear
the fractional change in volume
the fractional change in length
the pressure

Question # 4 of 10 ( Start time: 07:20:16 PM ) Total Marks: 1
Which of the following will remain unchanged when a sound wave travels in air or in water?
Select correct option:

Amplitude
Wavelength
Frequency
Speed

Question # 5 of 10 ( Start time: 07:21:36 PM ) Total Marks: 1
For a body to be in equilibrium under the combined action of several forces:
Select correct option:

all the forces must be applied at the same point
all of the forces form pairs of equal and opposite forces
any two of these forces must be balanced by a third force
the sum of the torques about any point must equal zero


Question # 6 of 10 ( Start time: 07:22:18 PM ) Total Marks: 1
Sound waves are
Select correct option:

longitudinal
transverse
partly longitudinal and partly transverse
sometimes longitudinal and sometimes transverse

Question # 7 of 10 ( Start time: 07:23:34 PM ) Total Marks: 1
Young’s modulus can be used to calculate the strain for a stress that is:
Select correct option:

just below the ultimate strength
just above the ultimate strength
well below the yield strength
well above the yield strength


Question # 8 of 10 ( Start time: 07:24:39 PM ) Total Marks: 1
Because a buoyant force acts in the opposite direction of gravity,
Select correct option:

objects submerged in water have a net force smaller than their weight.
objects submerged in water have a net force larger than their weight.
objects submerged in water have a net force equal to their weight.
objects submerged in water appear to weigh more than they do in air.
Question # 9 of 10 ( Start time: 07:26:04 PM ) Total Marks: 1
Young’s modulus can be correctly given in:
Select correct option:

N·m
N/m2
N/m
N·m/s
Question # 10 of 10 ( Start time: 07:26:45 PM ) Total Marks: 1
The frequency which is not audible to the human ear is
Select correct option:

50 Hz
500 Hz
5000 Hz
50000 Hz