Physics ESE Flashcards
To provide the same comfort, do we need higher room temperature in winter than summer?
A. No, because the absolute humidity is less in winter, so we lose less heat energy through vaporisation, and the skin surface becomes warmer
B. Yes because we lose more heat energy through radiation due to the colder walls, and the skin surface becomes colder in the winter
C. No, because the temperature sensation is determined only by the air temperature
D. Yes, because the absolute humidity is greater in winter, so we lose more heat energy through vaporisation, and the skin surface becomes colder
B. Yes because we lose more heat energy through radiation due to the colder walls, and the skin surface becomes colder in the winter
A car moves in a circular path at a constant speed. Which of the following is true?
A. The acceleration of the car is not zero and causes the change in the direction of the car’s velocity
B. The acceleration of the car is not zero and causes the car to speed up
C. The velocity of the car points towards the centre of the circular path
D. The acceleration of the car is tangential
E. The centripetal acceleration is zero
A. The acceleration of the car is not zero and causes the change in the direction of the car’s velocity
Which one of the following quantities is NOT a scalar?
A. acceleration
B. mass
C. time
D. work
E. electric current
A. acceleration
Work…
A. has a magnitude that does not depend on the angle between the direction of the displacement of the object and the force
B. can have either a positive or a negative sign depending on whether the force has a component perpendicular to the displacement of the body
C. has a non-zero value in the physical sense if a body is displaced in the direction perpendicular to the force acting on it
D. is scalar quantity
E. has the watt as its unit
D. is scalar quantity
According to the Fourier theorem, each periodic function can be describes as the… of harmonic oscillations with appropriate amplitude and frequency
A. scalar product
B. difference
C. ratio
D. vectorial product
E. sum
E. sum
1 Pa is
1 kg/(m x s^2)
Which statement is TRUE on the basis of Newton’s law of friction?
a. during the flow of real fluids, shear stress can be defined as the product of the shear force and the are of the fluid layer
b. viscosity is independent of the temperature
c. viscosity characterises the density (mass-to-volume ratio) of fluids, so for example the viscosity of oil is much less than that of mercury
d. According to this law, the force required to move the fluid layers on each other is directly proportional to the viscosity of the fluid
e. this law describes the flow of ideal fluids where internal friction is negligible
d. According to this law, the force required to move the fluid layers on each other is directly proportional to the viscosity of the fluid
Which one of the following statements is correct? about osmosis
a. osmotic pressure is inversely proportional to the hydrostatic pressure measured in the Pfeffer osmometer
b. components of higher- concentration solution always diffuse towards a less concentrated solution through the semipermeabe membrane
c. another term used for osmosis is free diffusion
d. according to van’t Hoff’s law, the osmotic pressure of diluted solutions is directly proportional to the concentration
e. according to van’t Hoff’s law, the osmotic pressure of diluted solutions is inversely proportional to the temperature
d. according to van’t Hoff’s law, the osmotic pressure of diluted solutions is directly proportional to the concentration
Which parameter of a sound wave should be increased in order to increase the sound level measured in decibels?
a. amplitude
b. polarisation
c. frequency
d. wavelength
e. speed of propagation
amplitude
An oscillatory motion must be simple harmonic if:
a. there is no friction
b. the motion is along the arc of a circle
c. the potentional energy is equal to the kinetic energy
d. the amplitude is small
e. the acceleration varies sinusoidally with time
the acceleration varies sinusoidally with time
choose the unit of molar heat capacity
a. numerically, the heat required to change the phase of 1kg of a substance without a change in temperature
b. numerically, the change in length of an object of unit length while the temperature increases by 1c
c. numerically, the heat required to increase the temperature of 1 mol of a substance by 1C
d. numerically, the heat required to increase the temperature of 1kg of a substance by 1C
c. numerically, the heat required to increase the temperature of 1 mol of a substance by 1C
You are choosing a screwdriver to loosen a stuck screw. Which of the following qualities of the screwdriver will allow you to deliver the most torque to the screw?
a. decreased length of the screwdriver shank
b. a handle with a small diameter
c. Increased length of the screwdriver shank
d. decreased width of the blade
e. a handle with a large diameter
a handle with a large diameter
The magnitude of intensive state parameters…
a. only depends on the volume of the system
b. can be defined only in isolated systems
c. is balanced when two or more systems are merged
d. depends on the location where they are measured in the system
e. only depends on the mass of the system
is balanced when two or more systems are merged
in an isometric contraction of a muscle
a. the length of the muscle changes and the stress is constant
b. neither the length of the muscle nor the stress changes
c. both the length of the muscle and the stress change
d. the length of the muscle is constant and the stress changes
e. the product of the changes in the muscle length and stress remains constant
the length of the muscle in constant and the stress changes
Which propert of a sound wave has the greatest influence on the sensation of the tone quality (timbre, acoustic ‘color’) of sound?
a. phase
b. frequcney
c. pressure amplitude
d. relative intensity of the overtones
e. attenuation
relative intensity of the overtones
