SI Units and Dimensional Formulae

SI Units and Dimensional Formulae

In motion with constant acceleration in a plane, what is true about the acceleration vector?

The acceleration vector in motion with constant acceleration remains constant in both magnitude and direction. This allows the motion to be analyzed as two independent one-dimensional motions along perpendicular axes. As per NCERT Class 11 Chapter 2, dimensional analysis checks correctness and SI units define base and derived quantities. This principle confirms that It changes magnitude is correct because its dimensions and unit match the physical quantity asked.

Ref: NCERT Class 11 Physics > Chapter 2: Units and Measurements > Topic: SI Units and Dimensional Formulae

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SI Units and Dimensional Formulae

In motion with constant acceleration in a plane, how are the x- and y-components of the motion related?

For motion with constant acceleration in a plane, the x- and y-components are independent of each other. The motion can be treated as two separate one-dimensional motions along perpendicular directions, with each component governed by its own constant acceleration. As per NCERT Class 11 Chapter 2, dimensional analysis checks correctness and SI units define base and derived quantities. This principle confirms that They are independent is correct because its dimensions and unit match the physical quantity asked.

Ref: NCERT Class 11 Physics > Chapter 2: Units and Measurements > Topic: SI Units and Dimensional Formulae

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SI Units and Dimensional Formulae

Time intervals measured by a clock give the following readings: 1.25 s, 1.24 s, 1.27 s, 1.21 s and 1.28 s. What is the p

A. Correct answer: Option A As per NCERT Class 11 Chapter 2, dimensional analysis checks correctness and SI units define base and derived quantities. This principle confirms that 1.6% is correct because its dimensions and unit match the physical quantity asked.

Ref: NCERT Class 11 Physics > Chapter 2: Units and Measurements > Topic: SI Units and Dimensional Formulae

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SI Units and Dimensional Formulae

Of the following quantities, which one has dimension different from the remaining three? \[CBSE-PMT 1989\]

A. As per NCERT Class 11 Chapter 2, dimensional analysis checks correctness and SI units define base and derived quantities. This principle confirms that Angular momentum is correct because its dimensions and unit match the physical quantity asked.

Ref: NCERT Class 11 Physics > Chapter 2: Units and Measurements > Topic: SI Units and Dimensional Formulae

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SI Units and Dimensional Formulae

Taking into account of the significant figures, what is the value of 9.99 m – 0.0099 m? \[NEET 2020 Phase I\]

Significant figures depend on least precise measurement. For 9.99 m (2 decimal places) minus 0.0099 m (4 decimal places), result 9.9801 m must be rounded to 2 decimal places as per subtraction rule in NCERT. So 9.98 m is correct, retaining 3 significant figures. Thus 9.98 m follows significant figure rules.

Ref: NCERT Class 11 Physics > Chapter 2: Units and Measurements > Topic: SI Units and Dimensional Formulae

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SI Units and Dimensional Formulae

How many significant figures are there in the measurement 0.023080?

Significant figures depend on least precise measurement. For 9.99 m (2 decimal places) minus 0.0099 m (4 decimal places), result 9.9801 m must be rounded to 2 decimal places as per subtraction rule in NCERT. So 9.98 m is correct, retaining 3 significant figures. Thus 3 follows significant figure rules.

Ref: NCERT Class 11 Physics > Chapter 2: Units and Measurements > Topic: SI Units and Dimensional Formulae

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SI Units and Dimensional Formulae

Which one of these quantities has a different dimension from the others?

Work, energy, and torque share the same dimensional formula \[ML2T−2\], while pressure is \[ML−1T−2\]. As per NCERT Class 11 Chapter 2, dimensional analysis checks correctness and SI units define base and derived quantities. This principle confirms that Pressure is correct because its dimensions and unit match the physical quantity asked.

Ref: NCERT Class 11 Physics > Chapter 2: Units and Measurements > Topic: SI Units and Dimensional Formulae

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SI Units and Dimensional Formulae

Which of the following is not a derived unit?

Derived units are formed by combining base units. Base units are fundamental and independent. As per NCERT Class 11 Chapter 2, dimensional analysis checks correctness and SI units define base and derived quantities. This principle confirms that Kilogram (kg) is correct because its dimensions and unit match the physical quantity asked.

Ref: NCERT Class 11 Physics > Chapter 2: Units and Measurements > Topic: SI Units and Dimensional Formulae

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SI Units and Dimensional Formulae

Which of the following quantities is dimensionless?

Reynolds number is a pure ratio and has no physical dimensions. As per NCERT Class 11 Chapter 2, dimensional analysis checks correctness and SI units define base and derived quantities. This principle confirms that Reynolds number is correct because its dimensions and unit match the physical quantity asked.

Ref: NCERT Class 11 Physics > Chapter 2: Units and Measurements > Topic: SI Units and Dimensional Formulae

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SI Units and Dimensional Formulae

Which of the following has the dimensional formula \[M0L0T0\]?

Dimensionless quantities like refractive index, strain, and angles have no physical dimensions. As per NCERT Class 11 Chapter 2, dimensional analysis checks correctness and SI units define base and derived quantities. This principle confirms that Strain is correct because its dimensions and unit match the physical quantity asked.

Ref: NCERT Class 11 Physics > Chapter 2: Units and Measurements > Topic: SI Units and Dimensional Formulae

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SI Units and Dimensional Formulae

If the unit of length is doubled, how is the unit of area affected?

Area is proportional to the square of length. So, if the unit of length doubles, the unit of area becomes four times larger. As per NCERT Class 11 Chapter 2, dimensional analysis checks correctness and SI units define base and derived quantities. This principle confirms that Four times is correct because its dimensions and unit match the physical quantity asked.

Ref: NCERT Class 11 Physics > Chapter 2: Units and Measurements > Topic: SI Units and Dimensional Formulae

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SI Units and Dimensional Formulae

Which one of the following pairs has different dimensions?

Pressure and stress both share the same dimensional formula \[ML−1T−2\], but energy has \[ML2T−2\]. As per NCERT Class 11 Chapter 2, dimensional analysis checks correctness and SI units define base and derived quantities. This principle confirms that Pressure and Energy is correct because its dimensions and unit match the physical quantity asked.

Ref: NCERT Class 11 Physics > Chapter 2: Units and Measurements > Topic: SI Units and Dimensional Formulae

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