Physics Answers

We have equal amounts of two identical ideal gases at the same temperature T but at different

pressures p1 and p2 in two containers. Containers are connected. Find the change in entropy.

Find the number of oxygen molecules in 0.1 kg, whose speeds lie between 195 and 205 m/s at

0C.

The atomic ratio between Uranium isotope 238U and 234U in a mineral sample is found

to be 1.8 × 104

. The half-life of 234U is 2.5 × 105 yrs. Find the hal-life of 238U.

Determine the magnetic field due to a very long solenoid, at an interior point of the solenoid, in terms of the current in the solenoid windings and the number of turns per unit length of the solenoid.

The polonium isotope 210

84 Po is unstable and emits a 5.30 MeV alpha particle. The

atomic mass of 210

84 Po is 20998 and that of 4

2He is 4.0026u. Identify the daughter nuclide

and find its atomic mass in u.

A circular current–carrying coil has a radius R. Determine the distance in terms of R, of a point on the axis from the centre of the coil where the magnetic field produced by the coil is 1/8 of its value at the centre of the coil.

. A permanent magnet is made of ferromagnetic material with a magnetization equals to 7.5 10 A/ m 5  . The magnet is in the form of a cylindrical road with a length of 6.00 cm and a diameter of 1.20 cm. Determine the magnetic dipole moment of the magnet.

A long straight copper wire of radius R carries a free current I. The current is distributed uniformly over the cross-section of the wire. Find the magnetizing field H outside and inside the wire

Show that the mass of radium (Mass number= 226, half-life = 1600 yrs) with an

activity of a curie (1Ci) is almost 1gm.

 A rectangular loop of conducting wire with sides 3.0 m and 1.0 m is perpendicular to a uniform magnetic field The magnitude of the magnetic field varies with time as B = 0.08 + 0.75 t, where B is in Teslas and t is in seconds. A battery of 12.0V and negligible resistance is connected in the loop as shown in the figure. (a) Determine the total emf in the circuit. (b) What is the direction of the current through the circuit? 19. What inductance will be needed to store 1.00 Wh of energy in a coil carrying a current of 20 A?