In a ferromagnetic material, below the curie temperature, a domain is defined as :

A bar magnet of length 14 cm is placed in the magnetic meridian with its north pole pointing towards the geographic north pole. A neutral point is obtained at a distance of 18 cm from the center of the magnet. If BH = 0.4 G, the magnetic moment of the magnet is : (1G = 10$$-$$4 T)

Which of the following statements are correct? (A) Electric monopoles do not exist whereas magnetic monopoles exist. (B) Magnetic field lines due to a solenoid at its ends and outside cannot be completely straight and confined. (C) Magnetic field lines are completely confined within a toroid. (D) Magnetic field lines inside a bar magnet are not parallel. (E) $$\chi$$ = $$-$$1 is the condition for a perfect diamagnetic material, where x is its magnetic susceptibility. Choose the correct answer from the options given below :

At an angle of 30$${}^{\circ }$$ to the magnetic meridian, the apparent dip is 45$${}^{\circ }$$. Find the true dip :

The magnetic susceptibility of a material of a rod is 499. Permeability in vacuum is 4$$\pi$$ $$\times$$ 10$$-$$7 H/m. Absolute permeability of the material of the rod is :

Choose the correct option

Statement I : The ferromagnetic property depends on temperature. At high temperature, ferromagnet becomes paramagnet. Statement II : At high temperature, the domain wall area of a ferromagnetic substance increases. In the light of the above statements, choose the most appropriate answer from the options given below :

Following plots show magnetization (M) vs magnetizing field (H) and magnetic susceptibility ($$\chi$$) vs temperature (T) graph : Which of the following combination will be represented by a diamagnetic material?

Four identical particles of equal masses 1 kg made to move along the circumference of a circle of radius 1 m under the action of their own mutual gravitational attraction. The speed of each particle will be :

Consider two satellites S1 and S2 with periods of revolution 1 hr. and 8 hr. respectively revolving around a planet in circular orbits. The ratio of angular velocity of satellite S1 to the angular velocity of satellite S2 is :

Two stars of masses m and 2m at a distance d rotate about their common centre of mass in free space. The period of revolution is :

A body weights 49N on a spring balance at the north pole. What will be its weight recorded on the same weighing machine, if it is shifted to the equator? [Use g = {{GM} \over {{R^2}}} = 9.8 ms$$-$$2 and radius of earth, R = 6400 km.]

A solid sphere of radius R gravitationally attracts a particle placed at 3R from its centre with a force F1. Now a spherical cavity of radius \left( {{R \over 2}} \right) is made in the sphere (as shown in figure) and the force becomes F2. The value of F1 : F2 is

Two satellites A and B of masses 200 kg and 400 kg are revolving round the earth at height of 600 km and 1600 km respectively. If TA and TB are the time periods of A and B respectively then the value of TB $$-$$ TA : [Given : radius of earth = 6400 km, mass of earth = 6 $$\times$$ 1024 kg]

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : The escape velocities of planet A and B are same. But A and B are of unequal mass. Reason R : The product of their mass and radius must be same. M1R1 = M2R2 In the light of the above statements, choose the most appropriate answer from the options given below :

A planet revolving in elliptical orbit has : A. a constant velocity of revolution. B. has the least velocity when it is nearest to the sun. C. its areal velocity is directly proportional to its velocity. D. areal velocity is inversely proportional to its velocity. E. to follow a trajectory such that the areal velocity is constant. Choose the correct answer from the options given below :

Find the gravitational force of attraction between the ring and sphere as shown in the diagram, where the plane of the ring is perpendicular to the line joining the centres. If $$\sqrt{8}$$R is the distance between the centres of a ring (of mass 'm') and a sphere (mass 'M') where both have equal radius 'R'.

The maximum and minimum distances of a comet from the Sun are 1.6 $$\times$$ 1012 m and 8.0 $$\times$$ 1010 m respectively. If the speed of the comet at the nearest point is 6 $$\times$$ 104 ms$$-$$1, the speed at the farthest point is :

A geostationary satellite is orbiting around an arbitrary planet 'P' at a height of 11R above the surface of 'P', R being the radius of 'P'. The time period of another satellite in hours at a height of 2R from the surface of 'P' is _________. 'P' has the time period of 24 hours.

The time period of a satellite in a circular orbit of radius R is T. The period of another satellite in a circular orbit of radius 9R is :