Class 11th

Assertion A: If in five complete rotations of the circular scale, the distance travelled on main scale of the screw gauge is 5 mm and there are 50 total divisions on circular scale, then least count is 0.001 cm.
Reason R: Least Count = Pitch / (Total divisions on circular scale)

In the light of the above statement, choose the most appropriate answer from the options given below:

A particle of mass 'm' is moving in time 't' on a trajectory given by r? = 10αt² i? + 5β(t-5) j?. Where α and β are dimensional constants. The angular momentum of the particle become the same as it was for t = 0 at time t = ______ seconds.

In the reported figure, there is a cyclic process ABCDA on a sample of 1mol of a diatomic gas. The temperature of the gas during the process A→B and C→D are T? and T? (T? > T?) respectively. Choose the correct option out of the following for work done if processes BC and DA are adiabatic.

The number of molecules in one litre of an ideal gas at 300K and 2 atmospheric pressure with mean kinetic energy 2 * 10? J per molecule is:

Assertion A: If A, B, C, D are four points on a semi-circular arc with centre at 'O' such that |AB| = |BC| = |CD|, then AB + AC + AD = 4AO + OB + OC
Reason R: Polygon law of vector addition yields AB + BC + CD = AD = 2AO

In the light of the above statements, choose the most appropriate answer from the options given below:

A light cylindrical vessel is kept on a horizontal surface. Area of base is A. A hole of cross-sectional area 'a' is made just at its bottom side. The minimum coefficient of friction necessary to prevent sliding the vessel due to the impact force of the emerging liquid is (a << A):

Three objects A, B and C are kept in a straight line on a frictionless horizontal surface. The masses of A, B and C are m, 2m and 2m respectively. A moves towards B with a speed of 9m/s and makes an elastic collision with it. Thereafter B makes a completely inelastic collision with C. All motions occur along same straight line. The final speed of C is:

The figure shows two solid discs with radius R and r respectively. If mass per unit area is same for both, what is the ratio of MI of bigger disc around axis AB (which is ⊥ to the plane of the disc and passing through its centre) to MI of smaller disc around one of its diameters lying on its plane? Given 'M' is the mass of the larger disc. (MI stands for moment of inertia)

Kindly consider the following figure

Two wires of same length and radius are joined end to end and loaded. The Young's modulii of the materials of the two wires are Y? and Y?. The combination behaves as a single wire then its Young's modulus is :