Two stars of masses 3 $$ \times $$ 10³¹ kg each, and at distance 2 $$ \times $$ 10¹¹ m rotate in a plane about their common centre of mass O. A meteorite passes through O moving perpendicular to the star’s rotation plane. In order to escape from the gravitational field of this double star, the minimum speed that meteorite should have at O is - (Take Gravitational constant; G = 6.67 $$ \times $$ 10^–11 Nm² kg^–2)

At some location on earth, the horizontal component of earth’s magnetic field is 18 × 10^–6 T. At this location, magnetic needle of length 0.12 m and pole strength 1.8 Am is suspended from its mid-point using a thread, it makes 45^o angle with horizontal in equilibrium. To keep this needle horizontal, the vertical force that should be applied at one of its ends is -

The electric field of a plane polarized electromagnetic wave in free space at time t = 0 is given by an expression $$\overrightarrow E \left( {x,y} \right) = 10\widehat j\cos \left[ {\left( {6x + 8z} \right)} \right].$$ The magnetic field $$\overrightarrow B $$(x,z, t) is given by $$-$$ (c is the velocity of light)

Half mole of an ideal monoatomic gas is heated at constant pressure of 1 atm from 20^oC to 90^oC. Work done by gas is close to – (Gas constant R = 8.31 J/mol.K)