Rotational Motion (NEET (NTANational Eligibility cum Medical Entrance Test) Physics): Questions 71  75 of 125
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Question number: 71
» Rotational Motion » Moment of Inertia
Assertion (Ꭺ)
If earth shrink (without change in mass) to half of its present size, length of the day would become 6 % increase.
Reason (Ꭱ)
When the size of the earth will change, its moment of inertia will also change.
Choices
Choice (4)  Response  

a.  Both Ꭺ and Ꭱ are false 

b.  Both Ꭺ and Ꭱ are true and Ꭱ is the correct explanation of Ꭺ 

c.  Ꭺ is true but Ꭱ is false 

d.  Both Ꭺ and Ꭱ are true but Ꭱ is NOT the correct explanation of Ꭺ 

Question number: 72
» Rotational Motion » Moment of Inertia
Question
Two discs of the same material and thickness have radii 0.4 m and 0.8 m. Their moments of inertia about their axes will be in the ratio of
Choices
Choice (4)  Response  

a.  1: 81 

b.  1: 27 

c.  1: 16 

d.  1: 3 

Question number: 73
» Rotational Motion » Values of Moments of Inertia
Question
Moment of inertia of a ring of mass M = 5 gm and radius R = 2 cm about an axis passing through its edge and parallel to its natural axis is
Choices
Choice (4)  Response  

a.  30 gmcm ^{2} 

b.  40 gmcm ^{2} 

c.  35 gmcm ^{2} 

d.  45 gmcm ^{2} 

Question number: 74
» Rotational Motion » Values of Moments of Inertia
Question
A constant torque of 31.4 Nm is exerted on a pivoted wheel. If angular acceleration of wheel is 4π rad/sec ^{2}, then the moment of inertia of the wheel is
Choices
Choice (4)  Response  

a.  4.5 kgm ^{2} 

b.  5.5 kgm ^{2} 

c.  2.5 kgm ^{2} 

d.  1.5 kgm ^{2} 

Question number: 75
» Rotational Motion » Moment of Inertia
Question
A disc is of mass M and radius R. The moment of inertia of it about an axis tangential to its edge and in polarize of the disc or parallel to its diameter is
Choices
Choice (4)  Response  

a. 


b. 


c. 


d. 

