A string of negligible mass going over clamped pully of mass supports block of mass as shown in the figure. The force on the pully by clamp is given by
mass-pully.png
  • $\sqrt{2}Mg$
  • $\sqrt2mg$
  • $\sqrt{\left(M+m\right)^2+m^2}g$
  • $\sqrt{\left(M+m\right)^2+M^2}g$
When a bicycle is in motion, the force of friction exerted by ground on the two wheels is such that, it acts
  • in the backward direction on the front wheel and in the forward direction on the rear wheel.
  • in the forward direction on the front wheel and in the backward direction on the rear wheel.
  • in the backward direction on both the front and the rear wheel.
  • in the forward direction on both front and the rear wheels.
A rocket with a lift-off mass $3.5\times{10}^4Kg$ is blasted upwards with an initial acceleration of $10m/s^2$. Then the initial thrust blast is
  • $3.5\times{10}^5N$
  • $7.0\times{10}^5N$
  • $14.0\times{10}^5N$
  • $1.75\times{10}^5N$
5 The block of mass $M$ is pulled along a horizontal frictionless surface by a rope of mass $m$. If a force $P$ is applied at the free end of the rope, the force exerted by the rope on the block is
  • $\frac{Pm}{\left(M+m\right)}$
  • $\frac{Pm}{\left(M-m\right)}$
  • $P$
  • $\frac{PM}{\left(M+m\right)}$
Three forces start action simultaneously on a particle moving with velocity $\vec{v}$. These forces are Represented in magnitude and direction by the three sides of a triangle $ABC$ as shown in the figure. The particle will now move with velocity
question-triangle.png
  • greater than $\vec{v}$
  • $\left|\vec{v}\right|$ in the direction of the largest force $BC$
  • $\vec{v}$ remaining unchanged
  • less than $\vec{v}$
A lift is moving down with acceleration a. A man in the lift drops a ball inside the lift. The acceleration of the ball is observed by the man in the lift and a man standing stationary on the ground are respectively.
  • $g,g$
  • $g-a, g-a $
  • $g-a, g$
  • $a,g$
A light spring balance hangs from the hook of the other light spring balance and a block of mass $M\, Kg$ hangs from the former one. Then the true statement about the scale reading is
  • Both the scales read $M\, Kg$ each
  • The scale of the lower one read $M\, Kg$ and of the upper one zero.
  • The reading of the two scales can be anything but the sum of readings will be $M\, Kg$
  • Both the scales read $M/2\, Kg$
A block rests on a rough inclined plane making an angle of ${30}^0$ with the horizontal. The coefficient of static friction between the block and the plane is $0.8$. If the frictional force on the block is $10\, N$, the mass of the block (in Kg) $\left(g=10m/s^2\right)$ is
  • 2.0
  • 4.0
  • 1.6
  • 2.5
A horizontal force of  is necessary to just hold a block stationary against a wall. The coefficient Of friction between the block is 0.The weight of the block is
question-figure-10.png
  • 20 N
  • 50 N
  • 100 N
  • 2 N
A smooth block is released at rest on a ${45}^0$ incline and then slides a distance $d$. The time taken to slide is $n$ times as much to slide on a rough incline than on a smooth incline. The coefficient of friction is
  • $\mu_k=1-\frac{1}{n^2}$
  • $\mu_k=\sqrt{1-\frac{1}{n^2}}$
  • $\mu_s=1-\frac{1}{n^2}$
  • $\mu_s=\sqrt{1-\frac{1}{n^2}}$
A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle. The motion of the particle takes place in a plane. It follows that
  • the velocity is constant
  • its acceleration is constant
  • its kinetic energy is constant
  • it moves in a straight line
An annular ring with inner and outer radii $R_1$ and $R_2$ is rolling without slipping with a uniform angular speed. The ratio of the forces $F_1/F_2$ experienced by two identical particles situated on the inner and outer parts of the ring is
  • $\frac{R_2}{R_1}$
  • $\left(\frac{R_1}{R_2}\right)^2$
  • $1$
  • $\frac{R_1}{R_2}$
Two frictionless inclined planes making angles ${30}^0$ and ${60}^0$ with the vertical are shown in the figure. Two blocks A and B are placed on two planes What is the relative vertical acceleration of A with respect to B?
question-14-triangle.png
  • $4.9m/s^2$ in vertical direction
  • $4.9m/s^2$ in horizontal direction
  • $9.8m/s^2$ in the vertical direction
  • zero
Question 15 Which of the four arrangements in the figure correctly shows the vector addition of two forces $F_1$ and $F_2$ to yield the third force $F_3$
question-15.png
  • a
  • b
  • c
  • d
A body of mass 5 Kg starts from the origin with an initial velocity $\vec{u}=\left(30\hat{i}+40\hat{j}\right) m/s$. If a constant force $\left(-6\hat{i}-5\hat{j}\right)N$ acts on the body, the time in which y component of velocity becomes zero is
  • 5 s
  • 20 s
  • 40 s
  • 80 s
Three blocks of mass 2 Kg, 3Kg, 5 Kg are connected to each other with a light string and are then placed on a frictionless surface as shown in the figure. The system is pulled by a force $F=10\, N$, then tension $T_1$ is
Question-17.png
  • 1 N
  • 5 N
  • 8 N
  • 10 N
A particle is moving in a circle with uniform speed $v$. In moving from a point to another diametrically opposite point,
  • the momentum changes by $mv$
  • the momentum changes by $2mv$
  • the kinetic energy changes by $\frac{1}{2}mv^2$
  • the kinetic energy changes by $mv^2$
A person is sitting in a lift accelerating upwards. The measured weight of a person will be,
  • less than actual weight
  • equal to actual weight
  • more than actual weight
  • zero
Which of the following statements is true?
  • velocity of light is constant in all media
  • velocity of light in vacuum is maximum
  • velocity of light is same in all reference frames
  • Laws of nature have identical form in all reference frames.
In following question, a statement of assertion is followed by a statement of reason. Mark the correct choice. Assertion: A rocket moves forward by pushing surrounding air backwards. Reason: It derives the necessary thrust to move forward, according to Newton’s third law of motion.
  • If both assertion and reason are true and reason is the correct explanation of assertion
  • If both assertion and reason are true but reason is not correct explanation of assertion.
  • If assertion is true and reason is false.
  • If both assertion and reason are false.
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