1
JEE Main 2018 (Online) 15th April Morning Slot
+4
-1
In a screw gauge, $$5$$ complete rotations of the screw cause it to move a linear distance of $$0.25$$ $$cm.$$ There are $$100$$ circular scale divisions. The thickness of a wire measured by this screw gauge gives a reading of $$4$$ main scale divisions and $$30$$ circular scale divisions. Assuming negligible zero error, the thickness of the wire is :
A
$$0.4300$$ $$cm$$
B
$$0.2150$$ $$cm$$
C
$$0.3150$$ $$cm$$
D
$$0.0430$$ $$cm$$
2
JEE Main 2017 (Online) 9th April Morning Slot
+4
-1
A physical quantity P is described by the relation

P = a$$^{{\raise0.5ex\hbox{\scriptstyle 1} \kern-0.1em/\kern-0.15em \lower0.25ex\hbox{\scriptstyle 2}}}$$ b2 c3 d$$-$$4

If the relative errors in the measurement of a, b, c and d respectively, are 2%, 1%, 3% and 5%, then the relative error in P will be :
A
8%
B
12%
C
32%
D
25%
3
JEE Main 2017 (Online) 8th April Morning Slot
+4
-1
Time (T), velocity (C) and angular momentum (h) are chosen as fundamentalquantities instead of mass, length and time. In terms of these, the dimensions of mass would be :
A
[M] = [T$$-$$1 C$$-$$2 h]
B
[M] = [T$$-$$1 C2 h]
C
[M] = [T$$-$$1 C$$-$$2 h$$-$$1]
D
[M] = [T C$$-$$2 h]
4
JEE Main 2017 (Offline)
+4
-1
The following observations were taken for determining surface tension T of water by capillary method:
diameter of capillary, D = 1.25 $$\times$$ 10-2 m
rise of water, h = 1.45 $$\times$$ 10-2m
Using g = 9.80 m/s2 and the simplified relation T = $${{rhg} \over 2} \times {10^3}N/m$$, the possible error in surface tension is closest to :
A
10 %
B
0.15 %
C
1.5 %
D
2.4 %
EXAM MAP
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