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Physics · UNITS AND MEASUREMENT
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Physics · UNITS AND MEASUREMENT
Match the following columns and select the correct choice: Column I (Base Quantity) Column II (SI Unit) A Mass P Ampere B Electric Current Q Kilogram C Thermodynamic Temperature R Candela D Luminous Intensity S Kelvin Which of the above statements is/are correct?
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The period of oscillation \( T \) of a gas bubble inside water created by an explosion depends on static pressure \( P \), density of water \( \rho \), and total energy of explosion \( E \). The time period \( T \) is proportional to:
Read answer →Physics · UNITS AND MEASUREMENT
When experimental data are subtracted, such as \( 12.9 \text{ g} - 7.06 \text{ g} \), according to the rules of arithmetic operations with significant figures, the result should be reported to:
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As per the revised SI base unit definitions, Planck's constant \( h \) has dimensions of \( [\text{M L}^2 \text{T}^{-1}] \). In a new system of units, the unit of length is halved (\( L' = 0.5\text{ L} \)) and the unit of time is doubled (\( T' = 2\text{ T} \)). If the numerical value of Planck's constant in the new system is twice its value in the SI system, then the new unit of mass \( M' \) in terms of the SI unit of mass \( M \) is:
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Which of the following quantities is dimensionless according to the SI system?
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In a new system of units, the unit of mass is chosen as \( \alpha\text{ kg} \), the unit of length as \( \beta\text{ m} \), and the unit of time as \( \gamma\text{ s} \). The magnitude of a energy of \( 4.2\text{ J} \) in this new system of units will be:
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When subtracting \( 7.06\text{ g} \) from \( 12.9\text{ g} \), the correct result reported with proper significant figures/decimal places is:
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In the CGS system, the unit of pressure is \( \text{dyne cm}^{-2} \). Given that \( 1\text{ bar} = 10^5\text{ Pa} \) (where \( 1\text{ Pa} = 1\text{ N m}^{-2} \)), what is the value of \( 1\text{ bar} \) expressed in \( \text{dyne cm}^{-2} \)?
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In the revised SI system (2018), the kilogram, kelvin, and ampere are defined by fixing the numerical values of which fundamental physical constants, respectively?
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According to the SI base units definitions in Table 1.1, the second is defined in terms of which of the following?
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The diameter of the earth is \( 1.28 \times 10^7\text{ m} \). Its order of magnitude is:
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A slide of area \( 1.75\text{ cm}^2 \) is projected onto a screen using a projector. The area of the image of the house on the screen is \( 1.55\text{ m}^2 \). The linear magnification of the projector-screen arrangement is closest to:
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The diameter of the Earth is \( 1.28 \times 10^7 \text{ m} \) and the diameter of a hydrogen atom is \( 1.06 \times 10^{-10} \text{ m} \). By how many orders of magnitude is the diameter of the Earth larger than that of the hydrogen atom?
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If a measured length is expressed in different units such as \( 23.08 \text{ mm} \), \( 2.308 \text{ cm} \), and \( 0.02308 \text{ m} \), how does the number of significant figures change?
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The density of a liquid in CGS units is \( 0.85\text{ g cm}^{-3} \). Its value in SI units (\( \text{kg m}^{-3} \)) is:
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Two physical quantities are measured as \( A = (12.9 \pm 0.1) \text{ g} \) and \( B = (7.06 \pm 0.01) \text{ g} \). The calculated difference \( (A - B) \) expressed to the correct number of decimal places and with its absolute uncertainty is:
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How many base units are there in the International System of Units (SI)?
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A student measures the mass of a metal block as \( 12.42\text{ g} \) and its volume as \( 2.5\text{ cm}^3 \). The density of the metal block, reported to the correct number of significant figures, should be:
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Which of the following numbers has four significant figures?
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A simple pendulum has a bob of mass \( m \) attached to a string of length \( l \), oscillating under acceleration due to gravity \( g \). Its time period is given by \( T = 2\pi \sqrt{\frac{l}{g}} \). If the length of the pendulum is increased by \( 21\% \) while keeping mass \( m \) and acceleration due to gravity \( g \) unchanged, the percentage increase in its time period \( T \) will be:
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According to the principle of dimensional homogeneity, which of the following statements is/are correct? (I) If a physical equation is dimensionally correct, it must be physically correct. (II) If a physical equation is dimensionally incorrect, it must be physically wrong. (III) Dimensionless constants cannot be verified using dimensional analysis.
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In a new system of units, the unit of mass is \( \alpha\text{ kg} \), the unit of length is \( \beta\text{ m} \), and the unit of time is \( \gamma\text{ s} \). The numerical value of \( 1\text{ Joule} \) of energy in this new system is:
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