Primary FRCA Course Physics Exam Prep Questions Flashcards
The following statements apply to equations of lines and curves:
The line y = 3 - 2x meets the y-axis at y = - 3
False. It is at y = 3. It meets the y-axis when x = 0, and feeding this into the equation gives y = 3 - 2(0) = 3.
The following statements apply to equations of lines and curves
In the parabola y = 4x^2 + 1, y is always positive
True. Since x^2 is always positive (or zero), y = 4x^2 + 1 will always be positive.
The following statements apply to equations of lines and curves
The parabola y = 4x^2 + 3 cuts the y-axis at x = 3
False. It cuts the y-axis at y = 3, which is the point at which x = 0.
The following statements apply to equations of lines and curves
An example of a rectangular hyperbola is Pressure x Volume = constant
True. Rectangular hyperbola are drawn when xy = 1
The following statements apply to equations of lines and curves
If y = 2x + 3, then x = (y - 3)/2
True. y = 2x + 3, therefore y - 3 = 2x and (y - 3)/2 = x.
More questions on mathematics
A minimum point on a curve y = f(x) is defined by dy/dx = 0
True. At both maximum and minimum points, the slope of the curve is 0.
More questions on mathematics
The value of e in y = ex depends on the units used to measure x
False. e is a mathematical constant (approximate value 2.71828) and doesn’t change.
More questions on mathematics
The calculation of cardiac output from a thermodilution curve is an application of differentiation
False. It is an example of integration
More questions on mathematics
A picofarad is 10-9 Farad
False. It is 10^-12
More questions on mathematics
For the exponential function C = Cmax.e^-kt, the time constant (tau) = 0.693/k
False. This is the expression for the half-life (t1/2). The time constant (tau) = 1/k.
The following statements apply to units of physical quantities
Velocity is rate of change of distance in m/s^2
False. m/s
The following statements apply to units of physical quantities
Force = mass x acceleration
True. Newton’s second law of motion
The following statements apply to units of physical quantities
Energy = force x velocity
False. Energy = force x distance
The following statements apply to units of physical quantities
Units of work are Joules
True
The following statements apply to units of physical quantities
Electrical current I = charge Q x time
False. Q = I x t
This question is about pressure
Pressure = force x area
False. P = F/A
This question is about pressure
Absolute pressure = Gauge pressure + atmospheric pressure
True.
This question is about pressure
Atmospheric pressure at sea level is 1.013 x 10^3 bar
False. It is 1.013 bar, or 1.013 x 10^5 N/m^2
This question is about pressure
The Pascal is the unit of pressure
True.
This question is about pressure
10 m water pressure is equivalent to 760 mmHg
True. They are both the value of atmospheric pressure at sea level. 10 m H2O = 1000 cm H2O.
In considering energy and work
Frictional losses mean that kinetic energy recovered is always less than the original potential energy
True
In considering energy and work
The units of energy are N/m
False. N.m
In considering energy and work
The kinetic energy contained in 2 kg object moving at a velocity of 4 m/sec is 32 J
False.
KE = 1/2mv2 = 16 J
In considering energy and work
The work done in compressing a ventilator bellows of cross sectional area A, through a pressure differential P through a displacement d is Pd/A
False. P.A.d
In considering energy and work
The work done in compressing a gas between two pressures and two volumes is proportional to the slope of the P-V curve between those two points
False. Area under P-V curve
This question is about heat exchange
Units of heat energy are Joules
True. Heat is a form of energy, so the units are those of energy
This question is about heat exchange
When a substance changes state it does so without changing its temperature
True. The change of state requires energy, latent heat, without any temperature change, in contrast to energy changes with no change of state
This question is about heat exchange
Condensation is the main form of heat loss in patients
False. it is radiation.
This question is about heat exchange
Temperature ˚K = ˚C + 273
True. eg 1˚C = 274 ˚K
This question is about heat exchange
The triple point of water occurs at 1 bar pressure and 273.16 K
False. It occurs at 0.006 bar and 273.16 K.
More questions on heat and temperature
In adiabatic energy exchange in a gas, the temperature remains constant
False. No temperature change is an isothermal process; adiabatic implies no heat supplied or lost.
More questions on heat and temperature
There is a span of 212˚ Fahrenheit between the ice point and boiling points of water.
False. Ice point at 32˚F, boiling point at 212˚ F, span 180˚ F.
More questions on heat and temperature
The critical temperature of water is 273.16 ˚C
False. It is 364.1˚C
More questions on heat and temperature
Water boils at a temperature which depends on ambient pressure
True. As boiling occurs when SVP = ambient pressure.
More questions on heat and temperature
Compression of a gas with work W raises its heat energy content by Q where Q=W
False. Second law of thermodynamics suggests Q. A simple statement of the law is that heat always flows spontaneously from hotter to colder regions of matter (or ‘downhill’ in terms of the temperature gradient).
In gases
V directly proportional to T is Charles’ Law
True
In gases
The Pressure-Temperature curve for a perfect gas crosses the Temp axis at 273.16˚K
False. This occurs at 0˚K [-273˚C].
In gases
Boyle’s Law written as P.V = nRT represents an isothermal energy change
True.
In gases
P1xV1 = P2xV2 is a form of Gay-Lussac’s law
False. It is a form of Boyle’s law.
In gases
P.Vy = nRT, where y = ratio of specific heat capacities at constant P and at constant V, represents an adiabatic energy change.
True. Adiabatic implies a process or condition in which heat does not enter or leave the system concerned.
More on gases
The critical temperature for oxygen is -180˚C
False. It is -116˚C
More on gases
The kinetic theory of gases takes account of forces of attraction between neighbouring molecules
False. It assumes perfectly elastic collisions between molecules.
More on gases
A vapour is a substance above its critical temperature
False. A substance above its critical temperature can be considered a gas.
More on gases
Nitrous oxide can exist as a liquid in temperate climates.
True. Its critical temperature is 36.40C
More on gases
The critical pressure of a gas is the pressure required to liquefy it above its critical temperature
False. A gas must be below its critical temperature to liquefy it.
In vapours
Saturated vapour pressure (SVP) is proportional to ambient pressure
False. SVP is related to temperature and not pressure
In vapours
Boiling of a liquid occurs when SVP = ambient pressure
True.
In vapours
In an uncompensated vaporiser the output falls with continued use
True. Vaporisation requires energy which is drawn from the liquid itself, whose temperature therefore falls.
In vapours
The output from a vaporiser at altitude decreases
False. The output increases.
In vapours
The high SVP of Desflurane makes it a potent agent
False. Potency is related to lipid solubility.
In considering humidity
Absolute humidity is measured in mg/L
True.
In considering humidity
Air at 100% humidity carries 47 mg H2O/L
False. 44 mg/ml.
In considering humidity
Relative humidity is the amount of water carried by a gas sample at temperature T compared to how much it can carry at room temperature
False. Relative humidity is amount of water actually carried at temp T compared to the max it could carry at T.
In considering humidity
A fall in ambient temperature produces condensation because the air carries more water vapour
False. Condensation produced because it carries less water vapour
In considering humidity
Fully saturated air at 21˚C has a saturated vapour pressure of 6.3 kPa.
False. 2.5 kPa. It is 6.3kPa at body temperature.
The following question concerns aspects of partial pressure of gases and vapours and diffusion
If the output from a vaporiser changes due to a change of ambient P it does not need recalibrating because the partial pressure of the volatile from the vaporiser is unchanged
True. It is the partial pressure of the agent which is pharmacologically important. If the pressure halves, the amount vaporised will double. This will mean that the partial pressure remains constant.
The following question concerns aspects of partial pressure of gases and vapours and diffusion
The partial pressure in the alveolus of nitrous oxide at 50% concentration in a gas mixture is about 70 kPa
False. It is about 50% of 101 kPa ie approximately 50kPa
The following question concerns aspects of partial pressure of gases and vapours and diffusion
The law by which we may calculate partial pressures from fractional concentrations is Henry’s law
False. This is Dalton’s law
The following question concerns aspects of partial pressure of gases and vapours and diffusion
Diffusion hypoxia is due to the partial pressure difference of nitrogen between the alveolus and the blood
False. While this partial pressure difference plays its part, the real cause of diffusion hypoxia is due to the difference in solubility in plasma between nitrogen and nitrous oxide.
The following question concerns aspects of partial pressure of gases and vapours and diffusion
Graham’s law of diffusion states that, for a given partial pressure difference, the rate of diffusion of a substance is inversely proportional to the square root of density
True.
In considering osmotic pressure
Equimolar solutions of sodium chloride and glucose exert similar osmotic pressure
False. Since NaCl dissociates into two osmotically active particles, it exerts twice the osmotic pressure of glucose
In considering osmotic pressure
One mole of any substance in 22.4 L water exerts an osmotic pressure of 1 bar
True.
In considering osmotic pressure
The addition of a solute to a solvent lowers its freezing point
True.
In considering osmotic pressure
The addition of a solute to a solvent lowers its SVP in relation to its osmotic pressure
True.
In considering osmotic pressure
The most osmotically active component in plasma are Na+ and Cl -ions
False. These cross capillary walls easily and do not act osmotically; albumin stays in the capillaries and exerts significant osmotic pressure.
In fluid mechanics
Laminar flow is the most efficient form of fluid transport
True. Less energy lost in eddies and noise.
In fluid mechanics
Laminar flow is more likely in viscous fluids
True. Increased viscosity reduces Reynolds’ number.
Re = ρuL / η
where:
ρ = density
u = flow velocity
L = length
η = viscosity
In fluid mechanics
For a given pressure drop, the flowrate in a pipe is more likely to increase if the diameter is doubled than if the length is halved
True. The Hagen-Poiseuille equation shows a fourth power relationship to diameter but a linear relationship to length
In fluid mechanics
Turbulent flow is less likely in fluids of high density
False. Reynolds number shows a direct relationship with density, and as Re increases, so does the likelihood of turbulence
In fluid mechanics
A venturi device can be used to measure flow rate
True.
In a simple electric circuit
Voltage drop is proportional to current flowing
True. This is Ohm’s law
In a simple electric circuit
In a series circuit, currents add together
False. The same current flows all through the circuit, the voltage drops across different elements varies
In a simple electric circuit
In a parallel circuit, the total equivalent resistance of the circuit is the sum of all component resistances
False. The inverse of the total resistance is the sum of the inverse component resistances.
In a simple electric circuit
Bridge circuits are used to amplify currents
False. Bridge circuits are used primarily to improve accuracy of current outputs when the inputs might be distorted.
In a simple electric circuit
In AC the voltage alternates between + 240V and - 240V
False. 240 V is the root mean square value; peak to peak is + 340 V to - 340 V
In circuits containing capacitors
In DC, the current initially flows then stops
True. A capacitor transmits current across the gap between its plates only when current is changing
In circuits containing capacitors
In a circuit containing a R and a C, the characteristic time constant = R.C
True
In circuits containing capacitors
Current is proportional to rate of change of voltage
True. I = C x dV/dt. Once the capacitor is fully charged, the rate of change of voltage is now zero, so the current flowing will also be zero.
In circuits containing capacitors
Current increases with frequency
True.
In circuits containing capacitors
A capacitor is used to store charge e.g. in a defibrillator
True.
With regard to inductors
The magnetic field induced in a coil induces a voltage which increases the driving voltage drop the coil.
False. The induced voltage opposes the driving voltage.
With regard to inductors
The time constant of a circuit containing L and R = L.R
False. L/R
With regard to inductors
Voltage is proportional to rate of change of current
True. V = L x dI/dt
With regard to inductors
Current is proportional to frequency
False. Voltage proportional to frequency.
With regard to inductors
In a transformer voltage change between primary and secondary windings is proportional to the windings ratio
True. V1/V2 = n1/n2
Regarding lasers:
Laser light is incoherent
False. It is coherent.
Regarding lasers:
Laser safety glasses should be marked with the wavelength and optical density for a specific type of laser
True.
Regarding lasers:
Laser safety glasses need only be worn by the operator
False. Should be worn by all those in the theatre.
Regarding lasers:
Helium Neon lasers are infra-red
False. It is a red light with a wavelength of 632.8 nm.
Regarding lasers:
CO2 laser light can be delivered by a fibre optic cable
False.
More on lasers:
Laser light is monochromatic
True.
More on lasers:
A Nd YAG laser is used to coagulate tissue
True.
More on lasers:
LASER stands for Light Attenuation by Stimulated Emission of Radiation
Light AMPLIFICATION by stimulated emission of radiation
More on lasers:
All lasers in medical use produce light with wavelengths between 400 and 700 nm
False. Many have wavelengths above the visible light spectrum. CO2 lasers for example have wavelengths over 10,000 nm.
More on lasers:
Fibre optic cables exploit total internal refraction to transmit light from one end to the other
False. Total internal REFLECTION.
In operational amplifiers
They are designed to have a high output resistance
False. A high input resistance.
In operational amplifiers
A high common mode rejection ratio means that all but the smallest input currents are rejected
False. High CMRR means a rejection at the input of all signals common to both inputs of a differential input.
In operational amplifiers
Can be linked to appropriate R and C components to give suitable bandwidth
True.
In operational amplifiers
Can be used with single or double inputs
False. Single inputs mean the output is prone to noise. The whole point of a op-amp is to use double input to cancel out noise (ie the voltage arriving at both inputs) and amplify what’s left.
In operational amplifiers
Similar op-amp circuitry can be used for ECG, EEG and EMG
False. These all have different amplitudes and frequencies.
