CBSE
An infinite number of charges, each equal to q, are placed along the x-axis at x=1, x=2, x = 4, x=8 and so on. What is the potential at x = 0 due to this set of charges ?
A circular disc rolls on a horizontal floor without slipping and the centre of the disc moves with a uniform velocity v. Which of the following values of the velocity at a point on the rim of the disc can have ?
v
− v
2v
Zero
A solid uniform sphere resting on a rough horizontal plane is given a horizontal impulse directed through its centre so that it starts sliding with an initial velocity v0. When it finally starts rolling without slipping the speed of its centre is
A large number of particles are placed around the origin, each at a distance R from the origin. The distance of the centre of mass of the system from the origin is
equal to R
less than equal to R
greater than R
greater than equal to R
Two particles A and B are moving as shown in the figure.
Their total angular momentum about the point O is
9.8 kg m2 / s
zero
52.7 kg m2 / s
37.9 kg m2 / s
An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 ms-1 and the second part of mass 2 kg moves with 8 ms-1 speed. If the third part flies off with 4 ms-1 speed, then its mass is
3 kg
5 kg
7 kg
17 kg
Three identical square plates rotate about the axes shown in the figure in such a way that their kinetic energies are equal. Each of the rotation axes passes through the centre of the square. Then the ratio of angular speeds ω1 : ω2 : ω3 is
1 : 1 : 1
A rod PQ of mass M and length L is hinged at end P. The rod is kept horizontal by a massless string tied to point Q as shown in figure. When string is cut, the initial angular acceleration of the rod is