363373
Assertion : The acceleration of a body down a rough inclined place greater than the acceleration due to gravity. Reason : The body is able to slide on a inclined plane only when its acceleration is less than acceleration due to gravity.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Consider a body of mass \(m\) placed on an inclined plane whose inclination is greater than the angle of repose. The body will slide down with an acceleration \(a\). The various forces acting on the body have been shown in figure. The force on the body down the inclined plane. Here, \(f=\mu m g \cos \theta\) \(i.e.,\,F = ma = mg\sin \theta - \mu \,mg\cos \theta \) or, \(a=g \sin \theta-\mu g \cos \theta=g(\sin \theta-\mu \cos \theta)\) clearly \(a < g . \Rightarrow a\) is not greater than \(\mathrm{g}\) \(\Rightarrow\) Assertion is false The result \((a < g)\) is for case of 'sliding' down. So correct option is (4)
PHXI05:LAWS OF MOTION
363374
Assertion : It is easier to pull a heavy object than to push it on a level ground. Reason : The magnitude of frictional force depends on the nature of the two surfaces in contact.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
When pulling a heavy object, the normal reaction force exerted by the Earth decreases, resulting in a decrease in the frictional force acting on the object. This makes it easier to pull a heavy object. So correct option is (2).
PHXI05:LAWS OF MOTION
363375
Which one of the following is not used to reduce friction?
1 Oil
2 Ball bearings
3 Sand
4 Graphite
Explanation:
Sand is used to increase the friction.
PHXI05:LAWS OF MOTION
363376
Assertion : Frictional forces are conservative forces. Reason : Potential energy cannot be associated with frictional force.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Frictional work is not entirely recoverable. When the force of friction is present, the total mechanical energy is not conserved. Therefore, frictional force is classified as a non-conservative or dissipative force. So correct option is (4).
363373
Assertion : The acceleration of a body down a rough inclined place greater than the acceleration due to gravity. Reason : The body is able to slide on a inclined plane only when its acceleration is less than acceleration due to gravity.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Consider a body of mass \(m\) placed on an inclined plane whose inclination is greater than the angle of repose. The body will slide down with an acceleration \(a\). The various forces acting on the body have been shown in figure. The force on the body down the inclined plane. Here, \(f=\mu m g \cos \theta\) \(i.e.,\,F = ma = mg\sin \theta - \mu \,mg\cos \theta \) or, \(a=g \sin \theta-\mu g \cos \theta=g(\sin \theta-\mu \cos \theta)\) clearly \(a < g . \Rightarrow a\) is not greater than \(\mathrm{g}\) \(\Rightarrow\) Assertion is false The result \((a < g)\) is for case of 'sliding' down. So correct option is (4)
PHXI05:LAWS OF MOTION
363374
Assertion : It is easier to pull a heavy object than to push it on a level ground. Reason : The magnitude of frictional force depends on the nature of the two surfaces in contact.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
When pulling a heavy object, the normal reaction force exerted by the Earth decreases, resulting in a decrease in the frictional force acting on the object. This makes it easier to pull a heavy object. So correct option is (2).
PHXI05:LAWS OF MOTION
363375
Which one of the following is not used to reduce friction?
1 Oil
2 Ball bearings
3 Sand
4 Graphite
Explanation:
Sand is used to increase the friction.
PHXI05:LAWS OF MOTION
363376
Assertion : Frictional forces are conservative forces. Reason : Potential energy cannot be associated with frictional force.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Frictional work is not entirely recoverable. When the force of friction is present, the total mechanical energy is not conserved. Therefore, frictional force is classified as a non-conservative or dissipative force. So correct option is (4).
363373
Assertion : The acceleration of a body down a rough inclined place greater than the acceleration due to gravity. Reason : The body is able to slide on a inclined plane only when its acceleration is less than acceleration due to gravity.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Consider a body of mass \(m\) placed on an inclined plane whose inclination is greater than the angle of repose. The body will slide down with an acceleration \(a\). The various forces acting on the body have been shown in figure. The force on the body down the inclined plane. Here, \(f=\mu m g \cos \theta\) \(i.e.,\,F = ma = mg\sin \theta - \mu \,mg\cos \theta \) or, \(a=g \sin \theta-\mu g \cos \theta=g(\sin \theta-\mu \cos \theta)\) clearly \(a < g . \Rightarrow a\) is not greater than \(\mathrm{g}\) \(\Rightarrow\) Assertion is false The result \((a < g)\) is for case of 'sliding' down. So correct option is (4)
PHXI05:LAWS OF MOTION
363374
Assertion : It is easier to pull a heavy object than to push it on a level ground. Reason : The magnitude of frictional force depends on the nature of the two surfaces in contact.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
When pulling a heavy object, the normal reaction force exerted by the Earth decreases, resulting in a decrease in the frictional force acting on the object. This makes it easier to pull a heavy object. So correct option is (2).
PHXI05:LAWS OF MOTION
363375
Which one of the following is not used to reduce friction?
1 Oil
2 Ball bearings
3 Sand
4 Graphite
Explanation:
Sand is used to increase the friction.
PHXI05:LAWS OF MOTION
363376
Assertion : Frictional forces are conservative forces. Reason : Potential energy cannot be associated with frictional force.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Frictional work is not entirely recoverable. When the force of friction is present, the total mechanical energy is not conserved. Therefore, frictional force is classified as a non-conservative or dissipative force. So correct option is (4).
363373
Assertion : The acceleration of a body down a rough inclined place greater than the acceleration due to gravity. Reason : The body is able to slide on a inclined plane only when its acceleration is less than acceleration due to gravity.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Consider a body of mass \(m\) placed on an inclined plane whose inclination is greater than the angle of repose. The body will slide down with an acceleration \(a\). The various forces acting on the body have been shown in figure. The force on the body down the inclined plane. Here, \(f=\mu m g \cos \theta\) \(i.e.,\,F = ma = mg\sin \theta - \mu \,mg\cos \theta \) or, \(a=g \sin \theta-\mu g \cos \theta=g(\sin \theta-\mu \cos \theta)\) clearly \(a < g . \Rightarrow a\) is not greater than \(\mathrm{g}\) \(\Rightarrow\) Assertion is false The result \((a < g)\) is for case of 'sliding' down. So correct option is (4)
PHXI05:LAWS OF MOTION
363374
Assertion : It is easier to pull a heavy object than to push it on a level ground. Reason : The magnitude of frictional force depends on the nature of the two surfaces in contact.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
When pulling a heavy object, the normal reaction force exerted by the Earth decreases, resulting in a decrease in the frictional force acting on the object. This makes it easier to pull a heavy object. So correct option is (2).
PHXI05:LAWS OF MOTION
363375
Which one of the following is not used to reduce friction?
1 Oil
2 Ball bearings
3 Sand
4 Graphite
Explanation:
Sand is used to increase the friction.
PHXI05:LAWS OF MOTION
363376
Assertion : Frictional forces are conservative forces. Reason : Potential energy cannot be associated with frictional force.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Frictional work is not entirely recoverable. When the force of friction is present, the total mechanical energy is not conserved. Therefore, frictional force is classified as a non-conservative or dissipative force. So correct option is (4).
