Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NTA Abhyas JEE Main2020PhysicsLaws of MotionPractice

A dynamometer D , which is a device used to measure force, is attached to two blocks of masses 6 kg and 4 kg . Forces of 20 N and 10 N are applied on the blocks as shown in the figure. The reading of the dynamometer is

Options

  1. A10   N
  2. B20   N
  3. C6   N
  4. D14   N

Correct answer

D. 14   N

Step-by-step solution

Make a free body diagram then write force equation for the blocks involving spring force. 20 - T = 6 a T - 10 = 4 a ∴ a = 1 and T = 14 N

Practice Laws of Motion on Quantrex Academy →

More from Laws of Motion

A block takes t time to slide down a plane inclined at 45° to the horizontal. If the surface is made smooth (frictionless), the block takes time t 2 to slide down the plane. The co 2026Two blocks ( P and Q ) with respectively masses 2 kg and 1.5 kg are joined by a massless thread. These blocks are mounted on a frictionless pulley which is fixed on the edge of a c 2026A mass of 1 kg is kept on an inclined plane with 30° inclination with respect to horizontal plane and it is at rest initially. Then the whole assembly is moved up with constant vel 2026Three masses m₁ = 4 kg, m₂ = 4 kg and m₃ = 6 kg are suspended from a fixed smooth frictionless pulley as shown in the figure below. The value of T₁/T₂ is _____. (take g = 10 m/s ^2 2026A wedge Y with mass of 10 kg and all frictionless surfaces and the inclined surface making 37° with horizontal. A block X with mass 2 kg is placed at the highest point of the wedge 2026At t=0 , a body of mass 100 g starts moving under the influence of a force (5 i +10 j ) N. After 2 s its position is (2x i +5y j ) m. The ratio x:y is ______. 2026The time taken by a block of mass m to slide down from the highest point to the lowest point on a rough inclined plane is 50 % more compared to the time taken by the same block on 2026A 0.5 kg mass is in contact against the inner wall of a cylindrical drum of radius 4 m rotating about its vertical axis. The minimum rotational speed of the drum to enable the mass 2026 Full Laws of Motion list All NTA Abhyas JEE Main PYQs