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#units

7 public questions tagged with this topic.

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

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

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

Which of the following quantities has different dimensions?

Pressure has the dimensional formula \[ML−1T−2\] while the others represent forms of energy or work. 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

Which of the following is a dimensionless constant?

Refractive index is the ratio of two similar quantities (speed of light), making it dimensionless. As per NCERT Class 11 Chapter 2, dimensional analysis checks correctness and SI units define base and derived quantities. This principle confirms that Refractive index 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

Which of the following pairs have the same dimensions?

Torque and work both have the dimensional formula \[ML2T−2\]. As per NCERT Class 11 Chapter 2, dimensional analysis checks correctness and SI units define base and derived quantities. This principle confirms that Work and Torque 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