1
JEE Main 2017 (Online) 9th April Morning Slot
+4
-1
Two tubes of radii r1 and r2, and lengths l1 and l2 , respectively, are connected in series and a liquid flows through each of them in stream line conditions. P1 and P2 are pressure differences across the two tubes.

If P2 is 4P1 and l2 is $${{{1_1}} \over 4}$$, then the radius r2 will be equal to :
A
r1
B
2r1
C
4r1
D
$${{{r_1}} \over 2}$$
2
JEE Main 2017 (Offline)
+4
-1
A man grows into a giant such that his linear dimensions increase by a factor of 9. Assuming that his density remains same, the stress in the leg will change by a factor of :
A
$${1 \over {81}}$$
B
9
C
$${1 \over {9}}$$
D
81
3
JEE Main 2016 (Online) 10th April Morning Slot
+4
-1
A thin 1 m long rod has a radius of 5 mm. A force of 50 $$\pi$$kN is applied at one end to determine its Young’s modulus. Assume that the force is exactly known. If the least count in the measurement of all lengths is 0.01 mm, which of the following statements is false ?
A
$${{\Delta \gamma } \over \gamma }$$ gets minimum contribution from the uncertainty in the length.
B
The figure of merit is the largest for the length of the rod.
C
The maximum value of $$\gamma$$ that can be determined is 2 $$\times$$ 1014 N/m2
D
$${{\Delta \gamma } \over \gamma }$$ gets its maximum contribution from the uncertainty in strain
4
JEE Main 2016 (Online) 10th April Morning Slot
+4
-1
A bottle has an opening of radius a and length b. A cork of length b and radius (a + $$\Delta$$a) where ($$\Delta$$a < < a) is compressed to fit into the opening completely (See figure). If the bulk modulus of cork is B and frictional coefficient between the bottle and cork is $$\mu$$ then the force needed to push the cork into the bottle is :

A
($$\pi$$ $$\mu$$ B b) $$\Delta$$a
B
(2$$\pi$$ $$\mu$$ B b) $$\Delta$$a
C
($$\pi$$ $$\mu$$ B b) a
D
(4$$\pi$$ $$\mu$$ B b) $$\Delta$$a
EXAM MAP
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