A disc is having an initial angular velocity of 4 rad/sec and an angular acceleration of 8 rad/sec2. Find the angle rotated in radians by the disc in 3 sec. A. 48 rad B. 36 rad C. 12 rad D. 24 rad

Collegedunia Team logo

Collegedunia Team

Content Curator

The Correct answer is (A)

The equation of rotational motion for constant angular acceleration is given by

θ = ωit + \(\frac{1}{2}\) αt2

Where, 

  • θ = angular displacement of the body in time t
  • ωi = initial angular velocity
  • α = angular acceleration

Given, 

Initial angular velocity, ωi = 4 rad/s

Angular acceleration, α = 8 rad/sec2

Time, t = 3 sec

Using the equation of rotational motion, angular displacement (θ) of the disc in time (t), is given by 

θ = (4 x 3) + ( \(\frac{1}{2}\) x 8 x 32)

⇒ θ = 12 + 36

⇒ θ = 48 rad.


Also Read:

CBSE CLASS XII Related Questions

  • 1.
    A part of a wire carrying \( 2.0 \, \text{A} \) current and bent at \( 90^\circ \) at two points is placed in a region of uniform magnetic field \( \vec{B} = -0.50 \, \hat{k} \, \text{T} \), as shown in the figure. Calculate the magnitude of the net force acting on the wire.


      • 2.
        In a Young's double-slit experiment, two waves each of intensity I superpose each other and produce an interference pattern. Prove that the resultant intensities at maxima and minima are 4I and zero respectively.


          • 3.
            A ray of light MN is incident normally on the face corresponding with side AB of a prism with an isosceles right-angled triangular base ABC. Trace the path of the ray as it passes through the prism when the refractive index of the prism material is \( \sqrt{2} \), and \( \sqrt{3} \).


              • 4.
                Nuclides with the same number of neutrons are called:

                  • Isobars
                  • Isotones
                  • Isotopes
                  • Isomers

                • 5.
                  The figure represents the variation of the electric potential \( V \) at a point in a region of space as a function of its position along the x-axis. A charged particle will experience the maximum force at:

                    • P
                    • Q
                    • R
                    • S

                  • 6.
                    Four long straight thin wires are held vertically at the corners A, B, C and D of a square of side \( a \), kept on a table and carry equal current \( I \). The wire at A carries current in upward direction whereas the current in the remaining wires flows in downward direction. The net magnetic field at the centre of the square will have the magnitude:

                      • \( \dfrac{\mu_0 I}{\pi a} \) and directed along OC
                      • \( \dfrac{\mu_0 I}{\pi a \sqrt{2}} \) and directed along OD
                      • \( \dfrac{\mu_0 I \sqrt{2}}{\pi a} \) and directed along OB
                      • \( \dfrac{2\mu_0 I}{\pi a} \) and directed along OA
                    CBSE CLASS XII Previous Year Papers

                    Comments


                    No Comments To Show