Q.1.
than one correct option Q423) In the figure, a ladder of mass m is shown leaning against a wall. It is in static equilibrium making an angle θ with the horizontal floor. The coefficient of friction between the wall and the ladder is µ1 and that between the floor and the ladder is µThe normal reaction of the wall on the ladder is N1 and that of the floor is NIf the ladder is about to slip, then[ IIT Advance 2013]
-
7%
a)
-
47%
b)
-
20%
c)
-
27%
d)
Explanation
Q.2.
A block of mass m1 = 1 kg another mass m2 = 2 kg, are placed together (see figure) on aninclined plane with angle of inclination θ. Various values of θ are given in List I. The coefficient of friction between the block m1 and the plane is always zero. The coefficientof static and dynamic friction between the block m2 and the plane are equal to µ = 0. In List II expressions for the friction on block m2 are given. Match the correct expression ofthe friction in List II with the angles given in List I, and choose the correct option. Theacceleration due to gravity is denoted by g. [Useful information : tan (5.5°) θ ≈ 0.1; tan(11.5°) ≈ 0.2; tan(16.5°) ≈ 0.3]
| List I | List II |
| P. θ = 5° | m2g sinθ |
| Q. θ = 10° | (m1 + m2) g sinθ |
| R. θ = 15° | µm2 g cosθ |
| S. θ = 20° | µ (m1 + m2) g cosθ |
-
33%
a) P-1, Q-1, R-1, S-3
-
8%
b) P-2, Q-2, R-2, S-3
-
25%
c) P-2, Q-2, R-2, S-4
-
33%
d) P-2, Q-2, R-3, S-3
Explanation
Q.3.
A person in a lift is holding a water jar, which has a small hole at the lower end of its side. When the lift is at rest, the water jet coming out of the hole hits the floor of the lift at a distance d of 1.2 m from the person. In the following, state of the lift’s motion is given in List I and the distance where the water jet hits the floor of the lift is given in List II. Match the statements from List I with those in List II and select the correct answer using the code given below the lists.
| List I | List II |
| P. Lift is accelerating vertically up. | d = 1.2 m |
| Q. Lift is accelerating vertically down with an acceleration less than the gravitational acceleration. | d > 1.2 m |
| R. Lift is moving vertically up with constant speed. | d < 1.2 m |
| S. Lift is falling freely. | No water leaks out of the jar |
-
20%
a) P-2, Q-3, R-2, S-4
-
0%
b) P-2, Q-3, R-1, S-4
-
50%
c) P-1, Q-1, R-1, S-4
-
30%
d) P-2, Q-3, R-1, S-1
Explanation
Q.4.
A uniform wooden stick of mass 1.6 kg and length “l” rests in an inclined manner on a smooth, vertical wall of height h(
-
10%
a)
-
30%
b)
-
20%
c)
-
40%
d)
Explanation
Q.5.
than one correct option Q428) A flat plate is moving normal to its plane through a gas under the action of a constant force F. The gas is kept at a very low pressure. The speed of the plate v is much less than the average speed u of the gas molecules. Which of the following options is/are true ?
-
0%
a) The resistive force experienced by the plate is proportional to v
-
70%
b) The pressure difference between the leading and trailing faces of the plate is proportional to uv.
-
10%
c) The plate will continue to move with constant non-zero acceleration, at all times
-
20%
d) At a later time the external force F balances the resistive force.
Explanation
Q.6.
A block A of mass m1 rests on a horizontal table. A light string connected to it passes over a frictionless pulley at the edge of table and from its other end another block B of mass m2 is suspended. The coefficient of kinetic friction between the block and the table is μk. When a block slide on the table what is the tension in the string
-
25%
-
17%
-
25%
-
33%
Explanation
