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NLM

968 Questions Start Allen Test
All Exams Allen Advance Errorless
Q351 Allen Newtons Laws of Motion MCQ
Statement-1: A reference frame attached to the earth is an inertial frame of reference. and Statement-2: In practical, Newton's laws can be applied in this frame of reference.
A.
Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1.
B.
Statement-1 is True, Statement-2 is True; Statement-2 is not a correct explanation for Statement-1.
C.
Statement-1 is True, Statement-2 is False.
D.
Statement-1 is False, Statement-2 is True.
Q352 Allen Newtons Laws of Motion MCQ
A lift is going up. The total mass of the lift and the passengers is 500 kg. The speed of lift varies with time as shown in figure. What will be the tension (in kN) in the rope pulling the lift at t = 27s. $g = 9.8 \, m/s^{2}$
A.
2
B.
4
C.
6
D.
8
Q353 Allen Newtons Laws of Motion MCQ
An airplane is moving horizontally with constant acceleration $5 \, m/s^{2}$ with a block of mass $2kg$ is hanging with it, which is at rest w.r.t. plane find angle $\theta$ which string makes with vertical?
A.
$\tan \theta = 2$
B.
$\cot \theta = 2$
C.
$\sin \theta = \frac {1}{2}$
D.
$\cos \theta = \frac{1}{2}$
Q354 Allen Newtons Laws of Motion MCQ
If acceleration (in $m/s^{2}$ ) of wedge (rightwards) so that block does not move w.r.t. wedge is $\frac{8n}{3}$ . Value of n.
A.
7
B.
8
C.
5
D.
9
Q355 Allen Newtons Laws of Motion MCQ
In the figure shown, blocks A and B move with velocities $v_{1}$ and $v_{2}$ along horizontal direction. Find the ratio of $\frac{v_{1}}{v_{2}}$ .
A.
$\frac{\cos\theta_1}{\cos\theta_2}$
B.
$\frac{\cos\theta_2}{\cos\theta_1}$
C.
$\frac{\sin\theta_2}{\sin\theta_1}$
D.
$\frac{\sin\theta_1}{\sin\theta_2}$
Q356 Allen Friction MCQ
A block is moving along y-axis with velocity 4 m/s on a plank relative to ground and the plank is moving along x-axis with velocity 3 m/s at any instant of time. The unit vector in direction of friction force acting on block at this moment of time is.
A.
$\frac{3\hat{i}+4\hat{j}}{5}$
B.
$\frac{3\hat{i}-4\hat{j}}{5}$
C.
$\frac{-3\hat{i}+4\hat{j}}{5}$
D.
$\frac{-3\hat{i}-4\hat{j}}{5}$
Q357 Allen Friction MCQ
For the system of blocks and pulley shown in the figure, acceleration of block is "a" and friction force acting on 10 kg block is F then :-
A.
$F = 60\ N$ , $a = 0\ m/s^2$
B.
$F = 50\ N$ , $a = \frac{20}{7}\ m/s^2$
C.
$F = 40\ N$ , $a = 0\ m/s^2$
D.
$F = 40\ N$ , $a = \frac{20}{7}\ m/s^2$
Q358 Allen Friction MCQ
A block of mass 2 kg is pressed against the vertical wall of coefficient of friction $\mu = 0.2$ . The value of friction force acting on the wall is :-
A.
$40\sqrt{3} N$ in upward direction
B.
$40\sqrt{3} N$ in downward direction
C.
$20N$ in upward direction
D.
No friction force acts on the block
Q359 Allen Friction MCQ
A block of mass M placed on rough surface of coefficient of friction equal to 3. If F is the $(4/5)$ of the minimum force required to just move, find out the force exerted by ground on the block.
A.
2.6 Mg
B.
Mg
C.
4Mg
D.
3.4 Mg
Q360 Allen Friction MCQ
The coefficient of friction between the block and the horizontal surface is $\mu$ as shown in figure. The block moves towards right under action of horizontal force F (figure-a). Sometime later another force P is applied to the block making an angle $\theta$ (such that $\tan \theta = \mu$ ) with vertical as shown in (figure - b). After application of force P, the acceleration of block shall Fig. (a) Fig. (b)
A.
increase
B.
decrease
C.
remains same
D.
information insufficient for drawing inference.
Q361 Allen Friction MCQ
A block of mass 2kg is at rest on a rough surface, of coefficient of friction 0.5. A force F is applied on the block, variation of force is represented in the figure. Speed of the block at t = 4 sec is:
A.
$2 0 m / s$
B.
$1 0 m / s$
C.
$5 m / s$
D.
$1 5 m / s$
Q362 Allen Friction MCQ
Figure shows a block kept on a rough inclined plane. The maximum external force down the incline for which the block remains at rest is 2N while the maximum external force up the incline for which the block is at rest is 10 N. The coefficient of static friction $\mu$ is
A.
$\frac{\sqrt{3}}{2}$
B.
$\frac{1}{\sqrt{6}}$
C.
$\sqrt{3}$
D.
$\frac{1}{\sqrt{3}}$
Q363 Allen Friction MCQ
Block A is placed on a rough wedge B which is placed on a smooth surface. The wedge has angle of inclination of $53^{\circ}$ and is imparted a horizontal acceleration g towards right. Block A is given an initial velocity $v_{0}$ with respect to wedge. Find the coefficient of friction for which block A moves with constant velocity $v_{0}$ with respect to wedge. ( $g = 10 \, m/s^{2}$ )
A.
$2 / 3$
B.
$3 / 7$
C.
$1 / 7$
D.
$1 / 3$
Q364 Allen Friction MCQ
A block of mass m is at rest with respect to a rough incline kept in elevator moving up with acceleration a. Which of following statements is /are correct.
A.
The contact force between block and incline is vertical.
B.
The contact force between block and incline is of magnitude $m(g - a)$ .
C.
The contact force between block and incline is perpendicular to the incline.
D.
The contact force is of magnitude mg cos θ.
Q365 Allen Friction MCQ
A block rests on an inclined plane at an angle $\theta$ with horizontal and there is friction between the block and the plane. The plane is accelerated to the right. If the block remains at the same position on the plane, which of the following pictures might show the free-body diagram for the block? All observation is drawn for inertial observer (All of the vectors shown are forces).
A.
B.
C.
D.
Q366 Allen Friction MCQ
Base angles of triangular wedge ABC are $37^{\circ}$ and $90^{\circ}$ . A uniform rope is kept over the wedge as shown in two figures. The maximum length of string which can be hanged vertically is $x_{1}$ (fig. I) and minimum length is $x_{2}$ (fig. II) in equilibrium. If $\frac{x_{1}}{x_{2}} = 3$ , find the value of coefficient of friction between rope and wedge. Fig(i) Fig(ii)
A.
0.5
B.
0.4
C.
0.6
D.
0.8
Q367 Allen Friction MCQ
In the figure shown a ring of mass M and a block of mass m are in equilibrium. The string is light and pulley P does not offer any friction and coefficient of friction between pole and M is $\mu$ . The frictional force offered by the pole on M is
A.
Mg directed up
B.
$\mu mg$ directed up
C.
$(M-m)g$ directed down
D.
$\mu mg$ directed down
Q368 Allen Friction MCQ
In the figure shown if friction coefficient of block 1kg and 2kg with inclined plane is $\mu_{1} = 0.5$ and $\mu_{2} = 0.4$ respectively, then
A.
both blocks will move together.
B.
both blocks will move separately.
C.
there is a non-zero contact force between two blocks.
D.
none of these
Q369 Allen Friction MCQ
For shown situation the acceleration of block is represented by : (Here t is time in second) $(g = 10 \, ms^{-2})$ So, acceleration of block remains same.
A.
B.
C.
D.
None of these
Q370 Allen Friction MCQ
In the figure shown, the friction coefficient between the block of mass 1 kg and the plank of mass 2 kg is 0.4 while that between the plank and floor is 0.1. A constant force ‘F’ starts acting horizontally on the upper 1 kg block. The acceleration of plank if F = 10 N is
A.
$2.5m / s^{2}$
B.
3.833 m/s $^{4}$
C.
0.5 m/s $^{4}$
D.
$1.0m / s^{2}$
Q371 Allen Friction MCQ
Three blocks of equal mass M are initially at rest on smooth floor. A force is applied to the system so that the three blocks are to move together. Mark the correct option.
A.
The minimum coefficient of friction required is $\frac{F}{3Mg}$ .
B.
The minimum coefficient of friction required is $\frac{F}{Mg}$ .
C.
The minimum coefficient of friction required is $\frac{F}{2Mg}$ .
D.
The minimum coefficient of friction required is $\frac{3F}{2Mg}$ .
Q372 Allen MULTIPLE CORRECT TYPE QUESTIONS MSQ
Consider a block suspended from a light string as shown in the figure. Which of the following pairs of forces constitute Newton's third law pair?
A.
Force with which string pulls on the ceiling and the force with which string pulls on block.
B.
Force with which string pulls on the block and weight of the block.
C.
Force acting on block due to the earth and force the block exerts on the earth.
D.
Force with which block pulls on string and force with which the string pulls on the block.
Q373 Allen MULTIPLE CORRECT TYPE QUESTIONS MSQ
A horse is pulling a cart on a rough surface. If take (horse + cart) as a system, then which of the following statement(s) is/are correct?
A.
Force by horse on cart is an internal force.
B.
Force by ground on horse is an external force.
C.
Force by cart on horse is an internal force.
D.
Force by ground on cart is an external force.
Q374 Allen MULTIPLE CORRECT TYPE QUESTIONS MSQ
For the system shown which of the option(s) are CORRECT :
A.
$N\cos \theta = mg$
B.
$N = mg\cos \theta$
C.
N - mg cos θ = ma
D.
$mg - N \cos \theta = ma \sin \theta$
Q375 Allen MULTIPLE CORRECT TYPE QUESTIONS MSQ
A ball is attached from the ceiling with help of three equal taut strings each making equal angle with vertical and equal angle with each other. The ball is under three forces of pull due to the string which are along the length of strings and the force of gravity acting vertically downwards.
A.
resultant of the four forces on the ball can be zero.
B.
resultant of the four forces on the ball can never be zero.
C.
If one string is cut and its force becomes zero, the ball can remain in equilibrium in that position.
D.
If one string is cut and its force becomes zero, the ball can never be in equilibrium in that position.