1
WB JEE 2020
+1
-0.25 A block of mass m rests on a horizontal table with a coefficient of static friction $$\mu$$. What minimum force must be applied on the block to drag it on the table?
A
$${\mu \over {\sqrt {1 + {\mu ^2}} }}$$ mg
B
$${{\mu - 1} \over {\mu + 1}}$$ mg
C
$${\mu \over {\sqrt {1 - {\mu ^2}} }}$$ mg
D
$$\mu$$ mg
2
WB JEE 2019
+1
-0.25 Two weights of the mass m1 and m2 (> m1) are joined by an inextensible string of negligible mass passing over a fixed frictionless pulley. The magnitude of the acceleration of the loads is
A
g
B
$${{{m_2} - {m_1}} \over {{m_2}}}$$
C
$${{{m_1}} \over {{m_2} + {m_1}}}g$$
D
$${{{m_2} - {m_1}} \over {{m_2} + {m_1}}}g$$
3
WB JEE 2018
+1
-0.25 A block of mass m2 is placed on a horizontal table and another block of mass m1 is placed on top of it. An increasing horizontal force F = at is exerted on the upper block but the lower block never moves as a result. If the coefficient of friction between the blocks is $$\mu$$1 and that between the lower block and the table is $$\mu$$2, then what is the maximum possible value of $$\mu$$1 / $$\mu$$2 ?
A
$${{{m_2}} \over {{m_1}}}$$
B
1 + $${{{m_2}} \over {{m_1}}}$$
C
$${{{m_1}} \over {{m_2}}}$$
D
1 + $${{{m_1}} \over {{m_2}}}$$
4
WB JEE 2018
+1
-0.25 The velocity (v) of a particle (under a force F) depends on its distance (x) from the origin (with x > 0) $$v \propto {1 \over {\sqrt x }}$$. Find how the magnitude of the force (F) on the particle depends on x?
A
$$F \propto {1 \over {{x^{3/2}}}}$$
B
$$F \propto {1 \over x}$$
C
$$F \propto {1 \over {{x^2}}}$$
D
$$F \propto x$$
WB JEE Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
Coordinate Geometry
Calculus
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