A wave has a period of 0.020 s and a wavelength of 2.0 m. What is its speed?
Correct answer C. 100 m/s
Subject / 480 questions
MDCAT ECAT Physics MCQs
Page 17 of MDCAT ECAT Physics multiple-choice questions with answers. Tap an option to check yourself.
Page 17 of 24
- Electromagnetic Induction 30
- Fluid Dynamics 30
- Electrostatics 30
- Electronics 30
- Electromagnetism 30
- Current Electricity 30
- Work and Energy 30
- Waves 30
- Vectors and Equilibrium 30
- Nuclear Physics 30
- Dawn of Modern Physics 30
- Thermodynamics 30
- Rotational and Circular Motion 30
- Atomic Spectra 30
- Alternating Current 30
- Force and Motion 30
If the amplitude of a progressive wave is doubled while its frequency is unchanged, the energy it carries per second becomes ____.
Correct answer A. four times as great
What is transferred from one place to another by a progressive wave?
Correct answer D. Energy, without net transfer of the medium
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Which of the following waves cannot be polarised?
Correct answer B. Sound waves in air
In which type of wave do the particles of the medium vibrate parallel to the direction of propagation, forming compressions and rarefactions?
Correct answer D. Longitudinal waves
Newton derived the formula v = √(P/ρ) for the speed of sound by assuming that the propagation of sound through a gas is ____.
Correct answer C. isothermal
Laplace corrected Newton’s formula for the speed of sound because the compressions and rarefactions ____.
Correct answer D. occur too quickly for heat to be exchanged, making the process adiabatic
Which of the following waves can travel through a vacuum?
Correct answer A. Light waves
Which of the following is a mechanical wave?
Correct answer A. Ultrasound
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A sound wave of frequency 500 Hz has a wavelength of 0.68 m in air. What is its speed?
Correct answer D. 340 m/s
For an ideal fluid flowing through a horizontal pipe of varying cross-section, where is the pressure lowest?
Correct answer B. Where the cross-section is narrowest
Water flows through a horizontal pipe, with speeds of 2.0 m/s at point X and 4.0 m/s at point Y. What is the pressure difference between X and Y (density of water = 1000 kg/m³)?
Correct answer C. 6.0 kPa
Water at pressure 1.200 × 10⁵ Pa flows at 1.0 m/s in a horizontal pipe of area 10 cm², which narrows to 5.0 cm². What is the pressure in the narrow part (density of water = 1000 kg/m³)?
Correct answer C. 1.185 × 10⁵ Pa
Wind blows at 30 m/s over a flat roof of area 100 m² while the air inside is still. What is the approximate upward force on the roof (density of air = 1.2 kg/m³)?
Correct answer D. 5.4 × 10⁴ N
Which explanation best accounts for the lift on an aeroplane wing?
Correct answer C. Air flows faster over the upper surface, so the pressure there is lower than below
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When an artery is narrowed by plaque deposits, how do blood speed and blood pressure change in the narrowed region?
Correct answer C. Speed increases and pressure decreases
A Venturi meter fitted in a horizontal pipe is used to measure ____.
Correct answer C. the speed of flow of a fluid
Two boats moving side by side, close together and parallel, tend to be drawn towards each other. What is the reason?
Correct answer A. Water between them moves faster, so the pressure there is lower
Why can two streamlines in a steady flow never cross each other?
Correct answer B. A fluid particle at the crossing point would have two velocities at once
Which of the following is NOT an assumption made for an ideal fluid?
Correct answer A. Its density changes noticeably with pressure