Physics miscellaneous
- The dimensional formula ML–1T–2 corresponds to
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ML–1T–2 is the dimension of any quantity that is force per unit area such as Pressure or Stress, Young’s Modulus, Bulk Modulus, Modulus of Rigidity, Energy Density. The Modulus of Elasticity is the ratio of the stress applied to a body or substance to the resulting strain within the elastic limit.
Correct Option: A
ML–1T–2 is the dimension of any quantity that is force per unit area such as Pressure or Stress, Young’s Modulus, Bulk Modulus, Modulus of Rigidity, Energy Density. The Modulus of Elasticity is the ratio of the stress applied to a body or substance to the resulting strain within the elastic limit.
- A man standing at the top of a tower has two spheres A and B. He drops sphere A downwards and throws sphere B horizontally at the same time. Which of the following is correct ?
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If no air resistance is present, the rate of descent depends only on how far the object has fallen, no matter how heavy the object is. This means that two objects will reach the ground at the same time if they are dropped simultaneously from the same height. This statement follows from the law of conservation of energy.
Correct Option: A
If no air resistance is present, the rate of descent depends only on how far the object has fallen, no matter how heavy the object is. This means that two objects will reach the ground at the same time if they are dropped simultaneously from the same height. This statement follows from the law of conservation of energy.
- Loudness of sound depends on
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Loudness depends on the amplitude of the sound wave. The larger the amplitude the more energy the sound wave contains therefore the louder the sound. The pitch of a note depends on the frequency of the source of the sound.
Correct Option: B
Loudness depends on the amplitude of the sound wave. The larger the amplitude the more energy the sound wave contains therefore the louder the sound. The pitch of a note depends on the frequency of the source of the sound.
- Distances of stars are measured in
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Light year is a unit of length used informally to express astronomical distances. It is most often used when expressing distances to stars and other distances on a galactic scale. It is equal to just under 10 trillion kilometres.
Correct Option: D
Light year is a unit of length used informally to express astronomical distances. It is most often used when expressing distances to stars and other distances on a galactic scale. It is equal to just under 10 trillion kilometres.
- In a particular system, the units of length, mass and time are chosen to be 10 cm, 10 g and 0.1 s respectively. The unit of force in this system will be equivalent to
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n2 = n1 
M1 
L1 T1 -2 M2 L2 T2
= 10= 1 103g 102cm 1s -2 10g 10cm 0.1s
Thus if the new unit of force is
10 X = 1 N or X = 0.1
Correct Option: A
n2 = n1 M1 L1 T1 -2 M2 L2 T2
= 10= 1 103g 102cm 1s -2 10g 10cm 0.1s
Thus if the new unit of force is
10 X = 1 N or X = 0.1
