1
JEE Main 2021 (Online) 20th July Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Two small drops of mercury each of radius R coalesce to form a single large drop. The ratio of total surface energy before and after the change is :
A
$${2^{{1 \over 3}}}:1$$
B
$$1:{2^{{1 \over 3}}}$$
C
2 : 1
D
1 : 2
2
JEE Main 2021 (Online) 20th July Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
The value of tension in a long thin metal wire has been changed from T1 to T2. The lengths of the metal wire at two different values of tension T1 and T2 are l1 and l2 respectively. The actual length of the metal wire is :
A
$${{{l_1} + {l_2}} \over 2}$$
B
$$\sqrt {{T_1}{T_2}{l_1}{l_2}} $$
C
$${{{T_1}{l_2} - {T_2}{l_1}} \over {{T_1} - {T_2}}}$$
D
$${{{T_1}{l_1} - {T_2}{l_2}} \over {{T_1} - {T_2}}}$$
3
JEE Main 2021 (Online) 17th March Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
An object is located at 2 km beneath the surface of the water. If the fractional compression $${{\Delta V} \over V}$$ is 1.36%, the ratio of hydraulic stress to the corresponding hydraulic strain will be ____________. [Given : density of water is 1000 kgm$$-$$3 and g = 9.8 ms$$-$$2]
A
1.44 $$\times$$ 107 Nm$$-$$2
B
1.44 $$\times$$ 109 Nm$$-$$2
C
1.96 $$\times$$ 107 Nm$$-$$2
D
2.26 $$\times$$ 109 Nm$$-$$2
4
JEE Main 2021 (Online) 17th March Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
When two soap bubbles of radii a and b (b > a) coalesce, the radius of curvature of common surface is :
A
$${{b - a} \over {ab}}$$
B
$${{a + b} \over {ab}}$$
C
$${{ab} \over {a + b}}$$
D
$${{ab} \over {b - a}}$$
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