363223
Assertion : Force is required to move a body uniformly along a circle. Reason : When a body is in uniform circular motion then its acceleration is zero.
1 Both assertion and reason are correct and reason is the correct explanation of assertion.
2 Both assertion and reason are correct but reason is not the correct explanation of assertion.
3 Assertion is correct but reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
When a body is moving in a circle, its speed remains same but velocity changes due to change in the direction of motion of body. As in circular motion the direction of velocity of body is changing so the acceleration cannot be zero.
PHXI05:LAWS OF MOTION
363224
A coin placed on a rotating table just slips when it is placed at a distance of \(1\;cm\) from the center If the angular velocity of the table is halved, it will just slip when placed at a distance of ____ from the centre.
1 \(2\;cm\)
2 \(1\;cm\)
3 \(8\;cm\)
4 \(4\;cm\)
Explanation:
Static friction, \(f_{s \max }=\mu m g=m \omega^{2} R \Rightarrow R=\dfrac{\mu g}{\omega^{2}}\) \(\therefore \frac{{{R^\prime }}}{R} = {\left( {\frac{\omega }{{{\omega ^\prime }}}} \right)^2} = {\left( {\frac{\omega }{{\omega /2}}} \right)^2} = 4\) \( \Rightarrow {R^\prime } = 4\;cm\). So distance from the center will be \(4\;cm\).
JEE - 2023
PHXI05:LAWS OF MOTION
363225
Assertion : Linear momentum of a body changes even when it is moving uniformly in a circle. Reason : In uniform circular motion velocity remains constant.
1 Both assertion and reason are correct and reason is the correct explanation of assertion.
2 Both assertion and reason are correct but reason is not the correct explanation of assertion.
3 Assertion is correct but reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
In uniform circular motion, the direction of motion changes, therefore velocity changes. As \(P = mv\) therefore momentum of a body also changes in uniform circular motion.
PHXI05:LAWS OF MOTION
363226
A bob is whirled in a horizontal plane by means of a string with an initial speed of \({\omega}\) \(rpm.\) The tension in the string is \({T}\). If speed becomes \({2 \omega}\) while keeping the same radius, the tension in the string becomes:
1 \({T}\)
2 \({4 T}\)
3 \({\dfrac{T}{4}}\)
4 \({\sqrt{2} T}\)
Explanation:
\(T = m\,\ell {\omega ^2}\) when angular velocity is doubled \(T' = m\,\ell \,{(2\omega )^2}\) \(T' = 4T\)
363223
Assertion : Force is required to move a body uniformly along a circle. Reason : When a body is in uniform circular motion then its acceleration is zero.
1 Both assertion and reason are correct and reason is the correct explanation of assertion.
2 Both assertion and reason are correct but reason is not the correct explanation of assertion.
3 Assertion is correct but reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
When a body is moving in a circle, its speed remains same but velocity changes due to change in the direction of motion of body. As in circular motion the direction of velocity of body is changing so the acceleration cannot be zero.
PHXI05:LAWS OF MOTION
363224
A coin placed on a rotating table just slips when it is placed at a distance of \(1\;cm\) from the center If the angular velocity of the table is halved, it will just slip when placed at a distance of ____ from the centre.
1 \(2\;cm\)
2 \(1\;cm\)
3 \(8\;cm\)
4 \(4\;cm\)
Explanation:
Static friction, \(f_{s \max }=\mu m g=m \omega^{2} R \Rightarrow R=\dfrac{\mu g}{\omega^{2}}\) \(\therefore \frac{{{R^\prime }}}{R} = {\left( {\frac{\omega }{{{\omega ^\prime }}}} \right)^2} = {\left( {\frac{\omega }{{\omega /2}}} \right)^2} = 4\) \( \Rightarrow {R^\prime } = 4\;cm\). So distance from the center will be \(4\;cm\).
JEE - 2023
PHXI05:LAWS OF MOTION
363225
Assertion : Linear momentum of a body changes even when it is moving uniformly in a circle. Reason : In uniform circular motion velocity remains constant.
1 Both assertion and reason are correct and reason is the correct explanation of assertion.
2 Both assertion and reason are correct but reason is not the correct explanation of assertion.
3 Assertion is correct but reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
In uniform circular motion, the direction of motion changes, therefore velocity changes. As \(P = mv\) therefore momentum of a body also changes in uniform circular motion.
PHXI05:LAWS OF MOTION
363226
A bob is whirled in a horizontal plane by means of a string with an initial speed of \({\omega}\) \(rpm.\) The tension in the string is \({T}\). If speed becomes \({2 \omega}\) while keeping the same radius, the tension in the string becomes:
1 \({T}\)
2 \({4 T}\)
3 \({\dfrac{T}{4}}\)
4 \({\sqrt{2} T}\)
Explanation:
\(T = m\,\ell {\omega ^2}\) when angular velocity is doubled \(T' = m\,\ell \,{(2\omega )^2}\) \(T' = 4T\)
363223
Assertion : Force is required to move a body uniformly along a circle. Reason : When a body is in uniform circular motion then its acceleration is zero.
1 Both assertion and reason are correct and reason is the correct explanation of assertion.
2 Both assertion and reason are correct but reason is not the correct explanation of assertion.
3 Assertion is correct but reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
When a body is moving in a circle, its speed remains same but velocity changes due to change in the direction of motion of body. As in circular motion the direction of velocity of body is changing so the acceleration cannot be zero.
PHXI05:LAWS OF MOTION
363224
A coin placed on a rotating table just slips when it is placed at a distance of \(1\;cm\) from the center If the angular velocity of the table is halved, it will just slip when placed at a distance of ____ from the centre.
1 \(2\;cm\)
2 \(1\;cm\)
3 \(8\;cm\)
4 \(4\;cm\)
Explanation:
Static friction, \(f_{s \max }=\mu m g=m \omega^{2} R \Rightarrow R=\dfrac{\mu g}{\omega^{2}}\) \(\therefore \frac{{{R^\prime }}}{R} = {\left( {\frac{\omega }{{{\omega ^\prime }}}} \right)^2} = {\left( {\frac{\omega }{{\omega /2}}} \right)^2} = 4\) \( \Rightarrow {R^\prime } = 4\;cm\). So distance from the center will be \(4\;cm\).
JEE - 2023
PHXI05:LAWS OF MOTION
363225
Assertion : Linear momentum of a body changes even when it is moving uniformly in a circle. Reason : In uniform circular motion velocity remains constant.
1 Both assertion and reason are correct and reason is the correct explanation of assertion.
2 Both assertion and reason are correct but reason is not the correct explanation of assertion.
3 Assertion is correct but reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
In uniform circular motion, the direction of motion changes, therefore velocity changes. As \(P = mv\) therefore momentum of a body also changes in uniform circular motion.
PHXI05:LAWS OF MOTION
363226
A bob is whirled in a horizontal plane by means of a string with an initial speed of \({\omega}\) \(rpm.\) The tension in the string is \({T}\). If speed becomes \({2 \omega}\) while keeping the same radius, the tension in the string becomes:
1 \({T}\)
2 \({4 T}\)
3 \({\dfrac{T}{4}}\)
4 \({\sqrt{2} T}\)
Explanation:
\(T = m\,\ell {\omega ^2}\) when angular velocity is doubled \(T' = m\,\ell \,{(2\omega )^2}\) \(T' = 4T\)
363223
Assertion : Force is required to move a body uniformly along a circle. Reason : When a body is in uniform circular motion then its acceleration is zero.
1 Both assertion and reason are correct and reason is the correct explanation of assertion.
2 Both assertion and reason are correct but reason is not the correct explanation of assertion.
3 Assertion is correct but reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
When a body is moving in a circle, its speed remains same but velocity changes due to change in the direction of motion of body. As in circular motion the direction of velocity of body is changing so the acceleration cannot be zero.
PHXI05:LAWS OF MOTION
363224
A coin placed on a rotating table just slips when it is placed at a distance of \(1\;cm\) from the center If the angular velocity of the table is halved, it will just slip when placed at a distance of ____ from the centre.
1 \(2\;cm\)
2 \(1\;cm\)
3 \(8\;cm\)
4 \(4\;cm\)
Explanation:
Static friction, \(f_{s \max }=\mu m g=m \omega^{2} R \Rightarrow R=\dfrac{\mu g}{\omega^{2}}\) \(\therefore \frac{{{R^\prime }}}{R} = {\left( {\frac{\omega }{{{\omega ^\prime }}}} \right)^2} = {\left( {\frac{\omega }{{\omega /2}}} \right)^2} = 4\) \( \Rightarrow {R^\prime } = 4\;cm\). So distance from the center will be \(4\;cm\).
JEE - 2023
PHXI05:LAWS OF MOTION
363225
Assertion : Linear momentum of a body changes even when it is moving uniformly in a circle. Reason : In uniform circular motion velocity remains constant.
1 Both assertion and reason are correct and reason is the correct explanation of assertion.
2 Both assertion and reason are correct but reason is not the correct explanation of assertion.
3 Assertion is correct but reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
In uniform circular motion, the direction of motion changes, therefore velocity changes. As \(P = mv\) therefore momentum of a body also changes in uniform circular motion.
PHXI05:LAWS OF MOTION
363226
A bob is whirled in a horizontal plane by means of a string with an initial speed of \({\omega}\) \(rpm.\) The tension in the string is \({T}\). If speed becomes \({2 \omega}\) while keeping the same radius, the tension in the string becomes:
1 \({T}\)
2 \({4 T}\)
3 \({\dfrac{T}{4}}\)
4 \({\sqrt{2} T}\)
Explanation:
\(T = m\,\ell {\omega ^2}\) when angular velocity is doubled \(T' = m\,\ell \,{(2\omega )^2}\) \(T' = 4T\)
