1
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Change Language
Two rods A and B of different materials are welded together as shown in figure. Their thermal conductivities are K1 and K2. The thermal conductivity of the composite will be

NEET 2017 Physics - Properties of Matter Question 83 English
A
$${{3\left( {{K_1} + {K_2}} \right)} \over 2}$$
B
$${K_1} + {K_2}$$
C
$$2\left( {{K_1} + {K_2}} \right)$$
D
$${{{K_1} + {K_2}} \over 2}$$
2
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Change Language
A physical quantity of the dimensions of length that can be formed out of c, G and $${{{e^2}} \over {4\pi {\varepsilon _0}}}$$ is [c is velocity of light, G is the universal constant of gravitation and e is charge]
A
$${c^2}{\left[ {G - {{{e^2}} \over {4\pi {\varepsilon _0}}}} \right]^{1/2}}$$
B
$${1 \over {{c^2}}}{\left[ {{{{e^2}} \over {G\,4\pi {\varepsilon _0}}}} \right]^{1/2}}$$
C
$${1 \over c}G{{{e^2}} \over {\,4\pi {\varepsilon _0}}}$$
D
$${1 \over {{c^2}}}{\left[ {G{{{e^2}} \over {\,4\pi {\varepsilon _0}}}} \right]^{1/2}}$$
3
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Change Language
Preeti reached the metro station and found that the escalator was not working. She walked up the sationary escalator in time t1. On another days, if she remains stationary on the the moving escalator, then the escalator takes her up in time t2. The time taken by her to walk up on the moving escalator will be
A
$${{{t_1}{t_2}} \over {{t_2} - {t_1}}}$$
B
$${{{t_1}{t_2}} \over {{t_2} + {t_1}}}$$
C
$${{t_1} - {t_2}}$$
D
$${{{t_1} + {t_2}} \over 2}$$
4
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Change Language
One end of string of length $$l$$ is connected to a particle of mass 'm' and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in circle with speed '$$\upsilon $$', the net force on the particle (directed towards centre) will be (T represents the tension in the string)
A
$$T + {{m{v^2}} \over l}$$
B
$$T - {{m{v^2}} \over l}$$
C
zero
D
$$T$$