Angular momentum of the particle rotating with a central force is constant due to

• Constant Force

• Constant linear momentum

• Zero Torque

• Zero Torque

22.

A force of  acts on O, the origin of the coordinate system. The torque about the point (1, −1) is

• 
• 
• 
• 

A thin circular ring of mass m and radius R is rotating about its axis with a constant angular velocity ω. Two objects each of mass M are attached gently to the opposite ends of a diameter of the ring. The ring now rotates with an angular velocity ω′

The rms value of the electric field of the light coming from the Sun is 720 N/C. The average total energy density of the electromagnetic wave is

• 3.3 × 10⁻³ J/m³

• 4.58 × 10⁻⁶ J/m³

• 6.37 × 10⁻⁹ J/m³

• 6.37 × 10⁻⁹ J/m³

Four point masses, each of value m, are placed at the corners of a square ABCD of side A. The moment of inertia through A and parallel to BD is

• m

• 2m

• √m

• √m

A wire elongates by 

• 2

• 2

A ‘T’ shaped object with dimensions shown in the figure, is lying on a smooth floor. A force F is applied at the point P parallel to AB, such that the object has only the translational motion without rotation. Find the location of P with respect to C

• 2

• 3

• 4

• 4

A particle is moving with a uniform speed in a circular orbit of radius R in a central force inversely proportional to the n^th power of R. If the period of rotation of the particle is T, then:

• $T\propto R^{n/2}$

• $T\propto R^{3/2} for any n$

• $T\propto R^{\frac{n}{2}+1}$

• $T\propto R^{\frac{n+1}{2}}$

A silver atom in a solid oscillates in simple harmonic motion in some direction with a frequency of 10¹²/sec. What is the force constant of the bonds connecting one atom with the other? (Mole wt. of silver = 108 and Avagadro number = 6.02 × 10²³ gm mole^–1)

• 5.5 N/m

• 6.4 N/m

• 7.1 N/m

• 2.2 N/m

A wheel rotating at 12 rev/sis brought to rest in 6 s. The average angular deceleration in rad/s² of the wheel during this process is

• −$4 \mathrm{\pi }$

• 4

• 72

• $1/\mathrm{\pi }$