355791
A particle moves from a point \((-2 \hat{i}+5 \hat{j})\) to \((4 \hat{j}+3 \hat{k})\) when a force of \((4 \hat{i}+3 \hat{j}) N\) is applied. How much work has been done by the force ?
355792
A mass \(M\) is lowered with the help of a string by a distance \(x\) at a constant acceleration \(\frac{g}{2}\). The magnitude of work done by the string will be
1 \(Mgx\)
2 \(\frac{1}{2}Mg{x^2}\)
3 \(\frac{1}{2}Mgx\)
4 \(Mg{x^2}\)
Explanation:
\(Mg - T = \frac{{Mg}}{2}\) or \(T = \frac{{Mg}}{2}\) or magnitude of work done\( = T \times x = \frac{{Mgx}}{2}\)
PHXI06:WORK ENERGY AND POWER
355793
Assertion : Work done is greater than zero, if angle between force and displacement is acute or both are in same direction. Reason : Work done by friction on a body sliding down an inclined plane is positive.
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:
\(W=F S \cos \theta\) We know \(\cos \,\,0^\circ = 1\) ( When \(F\) and \(S\) are in same direction ) \(\cos \,\,90^\circ = 0\) \(\Rightarrow\) Assertion is correct The work done by friction on a body sliding down an inclined plane is actually negative, not positive. So option (3) is correct. \(F=m g \sin \phi\) \(f=\mu m g \cos \phi\) Here \(\theta=\angle \vec{f}, \vec{S}\) \(\theta = {\rm{ }}180^\circ {\rm{ }}({\rm{as}}{\mkern 1mu} {\mkern 1mu} \vec f{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} \vec S{\mkern 1mu} {\mkern 1mu} {\rm{are}}{\mkern 1mu} {\mkern 1mu} {\rm{antiparallel}})\) \(\Rightarrow\) Work done by \(f\) is negative \(\Rightarrow\) Reason is incorrect \(\left( {\cos 180^\circ = - 1} \right)\) So correct option is (3)
PHXI06:WORK ENERGY AND POWER
355794
A man pushes a wall and fails to displace it. He does
1 Negative work
2 Maximum work
3 Positive but not maximum work
4 No work at all
Explanation:
There is no displacement.
PHXI06:WORK ENERGY AND POWER
355795
Assertion : No work is done if the displacement is zero. Reason : Work done by the force is defined to be the product of component of the force in the direction of the displacement and the magnitude of displacement.
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:
Work done \(W=F d \cos \theta\) If displacement is zero, i.e., \(\mathrm{d}=0, \mathrm{~W}=0\) So option (1) is correct.
355791
A particle moves from a point \((-2 \hat{i}+5 \hat{j})\) to \((4 \hat{j}+3 \hat{k})\) when a force of \((4 \hat{i}+3 \hat{j}) N\) is applied. How much work has been done by the force ?
355792
A mass \(M\) is lowered with the help of a string by a distance \(x\) at a constant acceleration \(\frac{g}{2}\). The magnitude of work done by the string will be
1 \(Mgx\)
2 \(\frac{1}{2}Mg{x^2}\)
3 \(\frac{1}{2}Mgx\)
4 \(Mg{x^2}\)
Explanation:
\(Mg - T = \frac{{Mg}}{2}\) or \(T = \frac{{Mg}}{2}\) or magnitude of work done\( = T \times x = \frac{{Mgx}}{2}\)
PHXI06:WORK ENERGY AND POWER
355793
Assertion : Work done is greater than zero, if angle between force and displacement is acute or both are in same direction. Reason : Work done by friction on a body sliding down an inclined plane is positive.
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:
\(W=F S \cos \theta\) We know \(\cos \,\,0^\circ = 1\) ( When \(F\) and \(S\) are in same direction ) \(\cos \,\,90^\circ = 0\) \(\Rightarrow\) Assertion is correct The work done by friction on a body sliding down an inclined plane is actually negative, not positive. So option (3) is correct. \(F=m g \sin \phi\) \(f=\mu m g \cos \phi\) Here \(\theta=\angle \vec{f}, \vec{S}\) \(\theta = {\rm{ }}180^\circ {\rm{ }}({\rm{as}}{\mkern 1mu} {\mkern 1mu} \vec f{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} \vec S{\mkern 1mu} {\mkern 1mu} {\rm{are}}{\mkern 1mu} {\mkern 1mu} {\rm{antiparallel}})\) \(\Rightarrow\) Work done by \(f\) is negative \(\Rightarrow\) Reason is incorrect \(\left( {\cos 180^\circ = - 1} \right)\) So correct option is (3)
PHXI06:WORK ENERGY AND POWER
355794
A man pushes a wall and fails to displace it. He does
1 Negative work
2 Maximum work
3 Positive but not maximum work
4 No work at all
Explanation:
There is no displacement.
PHXI06:WORK ENERGY AND POWER
355795
Assertion : No work is done if the displacement is zero. Reason : Work done by the force is defined to be the product of component of the force in the direction of the displacement and the magnitude of displacement.
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:
Work done \(W=F d \cos \theta\) If displacement is zero, i.e., \(\mathrm{d}=0, \mathrm{~W}=0\) So option (1) is correct.
355791
A particle moves from a point \((-2 \hat{i}+5 \hat{j})\) to \((4 \hat{j}+3 \hat{k})\) when a force of \((4 \hat{i}+3 \hat{j}) N\) is applied. How much work has been done by the force ?
355792
A mass \(M\) is lowered with the help of a string by a distance \(x\) at a constant acceleration \(\frac{g}{2}\). The magnitude of work done by the string will be
1 \(Mgx\)
2 \(\frac{1}{2}Mg{x^2}\)
3 \(\frac{1}{2}Mgx\)
4 \(Mg{x^2}\)
Explanation:
\(Mg - T = \frac{{Mg}}{2}\) or \(T = \frac{{Mg}}{2}\) or magnitude of work done\( = T \times x = \frac{{Mgx}}{2}\)
PHXI06:WORK ENERGY AND POWER
355793
Assertion : Work done is greater than zero, if angle between force and displacement is acute or both are in same direction. Reason : Work done by friction on a body sliding down an inclined plane is positive.
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:
\(W=F S \cos \theta\) We know \(\cos \,\,0^\circ = 1\) ( When \(F\) and \(S\) are in same direction ) \(\cos \,\,90^\circ = 0\) \(\Rightarrow\) Assertion is correct The work done by friction on a body sliding down an inclined plane is actually negative, not positive. So option (3) is correct. \(F=m g \sin \phi\) \(f=\mu m g \cos \phi\) Here \(\theta=\angle \vec{f}, \vec{S}\) \(\theta = {\rm{ }}180^\circ {\rm{ }}({\rm{as}}{\mkern 1mu} {\mkern 1mu} \vec f{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} \vec S{\mkern 1mu} {\mkern 1mu} {\rm{are}}{\mkern 1mu} {\mkern 1mu} {\rm{antiparallel}})\) \(\Rightarrow\) Work done by \(f\) is negative \(\Rightarrow\) Reason is incorrect \(\left( {\cos 180^\circ = - 1} \right)\) So correct option is (3)
PHXI06:WORK ENERGY AND POWER
355794
A man pushes a wall and fails to displace it. He does
1 Negative work
2 Maximum work
3 Positive but not maximum work
4 No work at all
Explanation:
There is no displacement.
PHXI06:WORK ENERGY AND POWER
355795
Assertion : No work is done if the displacement is zero. Reason : Work done by the force is defined to be the product of component of the force in the direction of the displacement and the magnitude of displacement.
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:
Work done \(W=F d \cos \theta\) If displacement is zero, i.e., \(\mathrm{d}=0, \mathrm{~W}=0\) So option (1) is correct.
355791
A particle moves from a point \((-2 \hat{i}+5 \hat{j})\) to \((4 \hat{j}+3 \hat{k})\) when a force of \((4 \hat{i}+3 \hat{j}) N\) is applied. How much work has been done by the force ?
355792
A mass \(M\) is lowered with the help of a string by a distance \(x\) at a constant acceleration \(\frac{g}{2}\). The magnitude of work done by the string will be
1 \(Mgx\)
2 \(\frac{1}{2}Mg{x^2}\)
3 \(\frac{1}{2}Mgx\)
4 \(Mg{x^2}\)
Explanation:
\(Mg - T = \frac{{Mg}}{2}\) or \(T = \frac{{Mg}}{2}\) or magnitude of work done\( = T \times x = \frac{{Mgx}}{2}\)
PHXI06:WORK ENERGY AND POWER
355793
Assertion : Work done is greater than zero, if angle between force and displacement is acute or both are in same direction. Reason : Work done by friction on a body sliding down an inclined plane is positive.
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:
\(W=F S \cos \theta\) We know \(\cos \,\,0^\circ = 1\) ( When \(F\) and \(S\) are in same direction ) \(\cos \,\,90^\circ = 0\) \(\Rightarrow\) Assertion is correct The work done by friction on a body sliding down an inclined plane is actually negative, not positive. So option (3) is correct. \(F=m g \sin \phi\) \(f=\mu m g \cos \phi\) Here \(\theta=\angle \vec{f}, \vec{S}\) \(\theta = {\rm{ }}180^\circ {\rm{ }}({\rm{as}}{\mkern 1mu} {\mkern 1mu} \vec f{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} \vec S{\mkern 1mu} {\mkern 1mu} {\rm{are}}{\mkern 1mu} {\mkern 1mu} {\rm{antiparallel}})\) \(\Rightarrow\) Work done by \(f\) is negative \(\Rightarrow\) Reason is incorrect \(\left( {\cos 180^\circ = - 1} \right)\) So correct option is (3)
PHXI06:WORK ENERGY AND POWER
355794
A man pushes a wall and fails to displace it. He does
1 Negative work
2 Maximum work
3 Positive but not maximum work
4 No work at all
Explanation:
There is no displacement.
PHXI06:WORK ENERGY AND POWER
355795
Assertion : No work is done if the displacement is zero. Reason : Work done by the force is defined to be the product of component of the force in the direction of the displacement and the magnitude of displacement.
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:
Work done \(W=F d \cos \theta\) If displacement is zero, i.e., \(\mathrm{d}=0, \mathrm{~W}=0\) So option (1) is correct.
355791
A particle moves from a point \((-2 \hat{i}+5 \hat{j})\) to \((4 \hat{j}+3 \hat{k})\) when a force of \((4 \hat{i}+3 \hat{j}) N\) is applied. How much work has been done by the force ?
355792
A mass \(M\) is lowered with the help of a string by a distance \(x\) at a constant acceleration \(\frac{g}{2}\). The magnitude of work done by the string will be
1 \(Mgx\)
2 \(\frac{1}{2}Mg{x^2}\)
3 \(\frac{1}{2}Mgx\)
4 \(Mg{x^2}\)
Explanation:
\(Mg - T = \frac{{Mg}}{2}\) or \(T = \frac{{Mg}}{2}\) or magnitude of work done\( = T \times x = \frac{{Mgx}}{2}\)
PHXI06:WORK ENERGY AND POWER
355793
Assertion : Work done is greater than zero, if angle between force and displacement is acute or both are in same direction. Reason : Work done by friction on a body sliding down an inclined plane is positive.
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:
\(W=F S \cos \theta\) We know \(\cos \,\,0^\circ = 1\) ( When \(F\) and \(S\) are in same direction ) \(\cos \,\,90^\circ = 0\) \(\Rightarrow\) Assertion is correct The work done by friction on a body sliding down an inclined plane is actually negative, not positive. So option (3) is correct. \(F=m g \sin \phi\) \(f=\mu m g \cos \phi\) Here \(\theta=\angle \vec{f}, \vec{S}\) \(\theta = {\rm{ }}180^\circ {\rm{ }}({\rm{as}}{\mkern 1mu} {\mkern 1mu} \vec f{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} \vec S{\mkern 1mu} {\mkern 1mu} {\rm{are}}{\mkern 1mu} {\mkern 1mu} {\rm{antiparallel}})\) \(\Rightarrow\) Work done by \(f\) is negative \(\Rightarrow\) Reason is incorrect \(\left( {\cos 180^\circ = - 1} \right)\) So correct option is (3)
PHXI06:WORK ENERGY AND POWER
355794
A man pushes a wall and fails to displace it. He does
1 Negative work
2 Maximum work
3 Positive but not maximum work
4 No work at all
Explanation:
There is no displacement.
PHXI06:WORK ENERGY AND POWER
355795
Assertion : No work is done if the displacement is zero. Reason : Work done by the force is defined to be the product of component of the force in the direction of the displacement and the magnitude of displacement.
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:
Work done \(W=F d \cos \theta\) If displacement is zero, i.e., \(\mathrm{d}=0, \mathrm{~W}=0\) So option (1) is correct.
