139427
What is the SI unit of Stefan- Boltzmann's constant \(\sigma\) ?
1 \(\mathrm{W} \mathrm{m}^{-2} \mathrm{~K}^{-4}\)
2 \(\mathrm{W} \mathrm{m}^{2} \mathrm{~K}^{4}\)
3 \(\mathrm{W} \mathrm{K}^{-4}\)
4 \(\operatorname{erg~s}^{-2} \mathrm{~K}^{-4}\)
Explanation:
A According to stefan's law, energy per unit time \((\mathrm{E} / \mathrm{t})=\sigma \mathrm{AT}^{4}\) \(\sigma=\frac{\mathrm{E} / \mathrm{t}}{\mathrm{AT}^{4}}\) \(\sigma=\frac{\mathrm{W}}{\mathrm{m}^{2} \mathrm{~K}^{4}}\) \(=\mathrm{Wm}^{-2} \mathrm{~K}^{-4}\) The SI unit of Stefan's constant \(=\mathrm{W} \cdot \mathrm{m}^{-2} \cdot \mathrm{K}^{-4}\) and CGS unit is \(=\) Erg.cm \({ }^{2}\)
AFMC-1986
Units and Measurements
139437
The unit of magnetic induction is
1 \(\mathrm{Wb} \mathrm{m}^{-2}\)
2 \(\mathrm{Wb} \mathrm{m}^{-1}\)
3 \(\mathrm{Wb} \mathrm{A}\)
4 \(\mathrm{Wb}\)
Explanation:
A \(\because\) Magnetic Induction \(=\frac{\text { Magnetic flux }}{\text { Area }}\) \(\therefore\) The unit of magnetic Inuction \(=\frac{\text { Weber }}{\text { meter }^{2}}\) \(=\mathrm{Wb} \cdot \mathrm{m}^{-2}\)
AP EAMCET (21.09.2020) Shift-I
Units and Measurements
139440
The unit of \(L / R\) is (where \(L=\) inductance and \(R\) \(=\) resistance)
1 \(\mathrm{sec}\)
2 \(\sec ^{-1}\)
3 volt
4 ampere
Explanation:
A \(\frac{L}{R}=\frac{\text { Henry }}{\text { ohm }}=\frac{\left(\frac{\text { volt }}{A / S}\right)}{\text { ohm }}=\frac{\text { volt.sec }}{\text { ohm. ampere }}\) \(\frac{\mathrm{L}}{\mathrm{R}}=\mathrm{sec}\) - \(\mathrm{L} / \mathrm{R}, \mathrm{CR}\) and \(\sqrt{\mathrm{LC}}\) all have dimensions of Time [T]. So unit will be second.
Manipal UGET-2019
Units and Measurements
139445
Which of the following is both unitless and dimensionless?
1 Angle
2 Solid angle
3 Mechanical equilvalent of heat
4 Refractive index
Explanation:
D Refractive index is the property of a material to bend light when passing through one medium to another medium. The ratio of the speed of light in a vacuum to the speed of light in a medium is called the refractive index of that medium. Reflective index \((\eta)=\frac{\text { Speed of light in vacuum }(\mathrm{c})}{\text { Speed of light in medium }(v)}\) Since it is the ratio of speed, it has no dimension or units.
139427
What is the SI unit of Stefan- Boltzmann's constant \(\sigma\) ?
1 \(\mathrm{W} \mathrm{m}^{-2} \mathrm{~K}^{-4}\)
2 \(\mathrm{W} \mathrm{m}^{2} \mathrm{~K}^{4}\)
3 \(\mathrm{W} \mathrm{K}^{-4}\)
4 \(\operatorname{erg~s}^{-2} \mathrm{~K}^{-4}\)
Explanation:
A According to stefan's law, energy per unit time \((\mathrm{E} / \mathrm{t})=\sigma \mathrm{AT}^{4}\) \(\sigma=\frac{\mathrm{E} / \mathrm{t}}{\mathrm{AT}^{4}}\) \(\sigma=\frac{\mathrm{W}}{\mathrm{m}^{2} \mathrm{~K}^{4}}\) \(=\mathrm{Wm}^{-2} \mathrm{~K}^{-4}\) The SI unit of Stefan's constant \(=\mathrm{W} \cdot \mathrm{m}^{-2} \cdot \mathrm{K}^{-4}\) and CGS unit is \(=\) Erg.cm \({ }^{2}\)
AFMC-1986
Units and Measurements
139437
The unit of magnetic induction is
1 \(\mathrm{Wb} \mathrm{m}^{-2}\)
2 \(\mathrm{Wb} \mathrm{m}^{-1}\)
3 \(\mathrm{Wb} \mathrm{A}\)
4 \(\mathrm{Wb}\)
Explanation:
A \(\because\) Magnetic Induction \(=\frac{\text { Magnetic flux }}{\text { Area }}\) \(\therefore\) The unit of magnetic Inuction \(=\frac{\text { Weber }}{\text { meter }^{2}}\) \(=\mathrm{Wb} \cdot \mathrm{m}^{-2}\)
AP EAMCET (21.09.2020) Shift-I
Units and Measurements
139440
The unit of \(L / R\) is (where \(L=\) inductance and \(R\) \(=\) resistance)
1 \(\mathrm{sec}\)
2 \(\sec ^{-1}\)
3 volt
4 ampere
Explanation:
A \(\frac{L}{R}=\frac{\text { Henry }}{\text { ohm }}=\frac{\left(\frac{\text { volt }}{A / S}\right)}{\text { ohm }}=\frac{\text { volt.sec }}{\text { ohm. ampere }}\) \(\frac{\mathrm{L}}{\mathrm{R}}=\mathrm{sec}\) - \(\mathrm{L} / \mathrm{R}, \mathrm{CR}\) and \(\sqrt{\mathrm{LC}}\) all have dimensions of Time [T]. So unit will be second.
Manipal UGET-2019
Units and Measurements
139445
Which of the following is both unitless and dimensionless?
1 Angle
2 Solid angle
3 Mechanical equilvalent of heat
4 Refractive index
Explanation:
D Refractive index is the property of a material to bend light when passing through one medium to another medium. The ratio of the speed of light in a vacuum to the speed of light in a medium is called the refractive index of that medium. Reflective index \((\eta)=\frac{\text { Speed of light in vacuum }(\mathrm{c})}{\text { Speed of light in medium }(v)}\) Since it is the ratio of speed, it has no dimension or units.
139427
What is the SI unit of Stefan- Boltzmann's constant \(\sigma\) ?
1 \(\mathrm{W} \mathrm{m}^{-2} \mathrm{~K}^{-4}\)
2 \(\mathrm{W} \mathrm{m}^{2} \mathrm{~K}^{4}\)
3 \(\mathrm{W} \mathrm{K}^{-4}\)
4 \(\operatorname{erg~s}^{-2} \mathrm{~K}^{-4}\)
Explanation:
A According to stefan's law, energy per unit time \((\mathrm{E} / \mathrm{t})=\sigma \mathrm{AT}^{4}\) \(\sigma=\frac{\mathrm{E} / \mathrm{t}}{\mathrm{AT}^{4}}\) \(\sigma=\frac{\mathrm{W}}{\mathrm{m}^{2} \mathrm{~K}^{4}}\) \(=\mathrm{Wm}^{-2} \mathrm{~K}^{-4}\) The SI unit of Stefan's constant \(=\mathrm{W} \cdot \mathrm{m}^{-2} \cdot \mathrm{K}^{-4}\) and CGS unit is \(=\) Erg.cm \({ }^{2}\)
AFMC-1986
Units and Measurements
139437
The unit of magnetic induction is
1 \(\mathrm{Wb} \mathrm{m}^{-2}\)
2 \(\mathrm{Wb} \mathrm{m}^{-1}\)
3 \(\mathrm{Wb} \mathrm{A}\)
4 \(\mathrm{Wb}\)
Explanation:
A \(\because\) Magnetic Induction \(=\frac{\text { Magnetic flux }}{\text { Area }}\) \(\therefore\) The unit of magnetic Inuction \(=\frac{\text { Weber }}{\text { meter }^{2}}\) \(=\mathrm{Wb} \cdot \mathrm{m}^{-2}\)
AP EAMCET (21.09.2020) Shift-I
Units and Measurements
139440
The unit of \(L / R\) is (where \(L=\) inductance and \(R\) \(=\) resistance)
1 \(\mathrm{sec}\)
2 \(\sec ^{-1}\)
3 volt
4 ampere
Explanation:
A \(\frac{L}{R}=\frac{\text { Henry }}{\text { ohm }}=\frac{\left(\frac{\text { volt }}{A / S}\right)}{\text { ohm }}=\frac{\text { volt.sec }}{\text { ohm. ampere }}\) \(\frac{\mathrm{L}}{\mathrm{R}}=\mathrm{sec}\) - \(\mathrm{L} / \mathrm{R}, \mathrm{CR}\) and \(\sqrt{\mathrm{LC}}\) all have dimensions of Time [T]. So unit will be second.
Manipal UGET-2019
Units and Measurements
139445
Which of the following is both unitless and dimensionless?
1 Angle
2 Solid angle
3 Mechanical equilvalent of heat
4 Refractive index
Explanation:
D Refractive index is the property of a material to bend light when passing through one medium to another medium. The ratio of the speed of light in a vacuum to the speed of light in a medium is called the refractive index of that medium. Reflective index \((\eta)=\frac{\text { Speed of light in vacuum }(\mathrm{c})}{\text { Speed of light in medium }(v)}\) Since it is the ratio of speed, it has no dimension or units.
139427
What is the SI unit of Stefan- Boltzmann's constant \(\sigma\) ?
1 \(\mathrm{W} \mathrm{m}^{-2} \mathrm{~K}^{-4}\)
2 \(\mathrm{W} \mathrm{m}^{2} \mathrm{~K}^{4}\)
3 \(\mathrm{W} \mathrm{K}^{-4}\)
4 \(\operatorname{erg~s}^{-2} \mathrm{~K}^{-4}\)
Explanation:
A According to stefan's law, energy per unit time \((\mathrm{E} / \mathrm{t})=\sigma \mathrm{AT}^{4}\) \(\sigma=\frac{\mathrm{E} / \mathrm{t}}{\mathrm{AT}^{4}}\) \(\sigma=\frac{\mathrm{W}}{\mathrm{m}^{2} \mathrm{~K}^{4}}\) \(=\mathrm{Wm}^{-2} \mathrm{~K}^{-4}\) The SI unit of Stefan's constant \(=\mathrm{W} \cdot \mathrm{m}^{-2} \cdot \mathrm{K}^{-4}\) and CGS unit is \(=\) Erg.cm \({ }^{2}\)
AFMC-1986
Units and Measurements
139437
The unit of magnetic induction is
1 \(\mathrm{Wb} \mathrm{m}^{-2}\)
2 \(\mathrm{Wb} \mathrm{m}^{-1}\)
3 \(\mathrm{Wb} \mathrm{A}\)
4 \(\mathrm{Wb}\)
Explanation:
A \(\because\) Magnetic Induction \(=\frac{\text { Magnetic flux }}{\text { Area }}\) \(\therefore\) The unit of magnetic Inuction \(=\frac{\text { Weber }}{\text { meter }^{2}}\) \(=\mathrm{Wb} \cdot \mathrm{m}^{-2}\)
AP EAMCET (21.09.2020) Shift-I
Units and Measurements
139440
The unit of \(L / R\) is (where \(L=\) inductance and \(R\) \(=\) resistance)
1 \(\mathrm{sec}\)
2 \(\sec ^{-1}\)
3 volt
4 ampere
Explanation:
A \(\frac{L}{R}=\frac{\text { Henry }}{\text { ohm }}=\frac{\left(\frac{\text { volt }}{A / S}\right)}{\text { ohm }}=\frac{\text { volt.sec }}{\text { ohm. ampere }}\) \(\frac{\mathrm{L}}{\mathrm{R}}=\mathrm{sec}\) - \(\mathrm{L} / \mathrm{R}, \mathrm{CR}\) and \(\sqrt{\mathrm{LC}}\) all have dimensions of Time [T]. So unit will be second.
Manipal UGET-2019
Units and Measurements
139445
Which of the following is both unitless and dimensionless?
1 Angle
2 Solid angle
3 Mechanical equilvalent of heat
4 Refractive index
Explanation:
D Refractive index is the property of a material to bend light when passing through one medium to another medium. The ratio of the speed of light in a vacuum to the speed of light in a medium is called the refractive index of that medium. Reflective index \((\eta)=\frac{\text { Speed of light in vacuum }(\mathrm{c})}{\text { Speed of light in medium }(v)}\) Since it is the ratio of speed, it has no dimension or units.
