1
WB JEE 2017
MCQ (Single Correct Answer)
+1
-0.25
Change Language
Three vectors $$\overrightarrow A $$ = a$$\widehat i$$ + $$\widehat j$$ + $$\widehat k$$; $$\overrightarrow B $$ = $$\widehat i$$ + b$$\widehat j$$ + $$\widehat k$$ and $$\overrightarrow C $$ = $$\widehat i$$ + $$\widehat j$$ + c$$\widehat k$$ are mutually perpendicular ($$\widehat i$$, $$\widehat j$$ and k are unit vectors along X, Y and Z-axes respectively). The respective values of a, b and c are
A
0, 0, 0
B
$$ - {1 \over 2}$$, $$ - {1 \over 2}$$, $$ - {1 \over 2}$$
C
1, $$-$$1, 1
D
$${1 \over 2}$$, $${1 \over 2}$$, $${1 \over 2}$$
2
WB JEE 2017
MCQ (Single Correct Answer)
+1
-0.25
Change Language
A block of mass 1 kg starts from rest at x = 0 and moves along the X-axis under the action of a force F = kt, where t is time and k = 1 Ns$$-$$1. The distance the block will travel in 6 seconds is
A
36 m
B
72 m
C
108 m
D
18 m
3
WB JEE 2017
MCQ (Single Correct Answer)
+2
-0.5
Change Language
A particle with charge Q coulomb, tied at the end of an inextensible string of length R metre, revolves in a vertical plane. At the centre of the circular trajectory, there is a fixed charge of magnitude Q coulomb. The mass of the moving charge M is such that $$Mg = {{{Q^2}} \over {4\pi {\varepsilon _0}{R^2}}}$$. If at the highest position of the particle, the tension of the string just vanishes, the horizontal velocity at the lowest point has to be
A
0
B
$$2\sqrt {gR} $$
C
$$\sqrt {2gR} $$
D
$$\sqrt {5gR} $$
4
WB JEE 2017
MCQ (Single Correct Answer)
+2
-0.5
Change Language
A bullet of mass 4.2 $$ \times $$ 10$$-$$2 kg, moving at a speed of 300 ms$$-$$1, gets stuck into a block with a mass 9 times that of the bullet. If the block is free to move without any kind of friction, the heat generated in the process will be
A
45 cal
B
405 cal
C
450 cal
D
1701 cal
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12