A student uses dimensional analysis to analyze the time () it takes for a capacitor (C) to discharge through a resistor (R). They correctly identify that depends on R and C. However, they are unable to derive the precise relationship . What limitation of dimensional analysis explains this?
Dimensional analysis cannot reveal purely numerical relationships between variables.
The analysis requires knowledge of the initial charge on the capacitor, which is not provided.
Dimensional analysis cannot handle exponential decay processes.
The relationship between , R, and C is logarithmic, not a power law.
Related Questions
If the formula for the velocity of a wave is given by , where is tension and is mass per unit length. Using dimensional analysis, which aspect of this formula cannot be derived?
The dimensions of velocity
The dimensions of tension
The dimensions of mass per unit length
That the relationship is a square root
Can dimensional analysis derive equations involving trigonometric functions?
Yes
No
Sometimes
Depends on the specific function
Which of these is a limitation of dimensional analysis?
It can be used to convert units.
It can check the correctness of an equation.
It cannot determine the nature of a physical quantity if it depends on more than three fundamental dimensions.
It can derive relationships between physical quantities.
In a vernier callipers, divisions on the vernier scale coincide with divisions on the main scale. If each division on the main scale is mm, find the vernier constant (in cm).
Dimensional analysis can help in deriving relationships between physical quantities. However, it cannot:
Check the homogeneity of physical equations
Convert units from one system to another
Deduce the dimensions of a physical quantity
Distinguish between two physical quantities having the same dimensions
Dimensional analysis is used to check the validity of an equation relating the speed of sound (v) in a gas to its pressure (P) and density (). Which limitation prevents dimensional analysis from distinguishing between and ?
It cannot determine dimensionless constants.
It cannot handle fractional exponents.
It assumes a linear relationship between variables.
It fails when more than three variables are involved.
A student uses dimensional analysis to analyze the time () it takes for a capacitor (C) to discharge through a resistor (R). They correctly identify that depends on R and C. However, they are unable to derive the precise relationship . What limitation of dimensional analysis explains this?
Dimensional analysis cannot reveal purely numerical relationships between variables.
The analysis requires knowledge of the initial charge on the capacitor, which is not provided.
Dimensional analysis cannot handle exponential decay processes.
The relationship between , R, and C is logarithmic, not a power law.
Dimensional analysis cannot be used to derive relationships containing:
Powers of quantities
Products of quantities
Ratios of quantities
Exponential functions
The relative density of the material of a body is the ratio of its weight in air and the loss of its weight in water. By using a spring balance, the weight of the body in air in measured to be 5.00 0.05N. The weight of the body in water is measured to be 4.00 0.05N. Then the maximum possible percentage error in relative density is
11%
1%
9%
7%
Dimensional analysis can be used to:
Determine the exact value of gravitational constant
Check the dimensional homogeneity of an equation
Find the value of trigonometric functions in an equation
Derive the exact equation for a physical phenomenon