Two charged thin infinite plane sheets of
uniform surface charge density $${\sigma _ + }$$ and $${\sigma _ - }$$,
where |$${\sigma _ + }$$| > |$${\sigma _ - }$$|, intersect at right angle.
Which of the following best represents the
electric field lines for this system :

A small bar magnet placed with its axis
at 30^o with an external field of 0.06 T
experiences a torque of 0.018 Nm. The
minimum work required to rotate it from its
stable to unstable equilibrium position is :

A beam of plane polarised light of large
cross-sectional area and uniform intensity
of 3.3 Wm^-2 falls normally on a
polariser (cross sectional area 3 $$ \times $$ 10^-4 m²) which
rotates about its axis with an angular speed
of 31.4 rad/s. The energy of light passing through
the polariser per revolution, is close to :

The specific heat of water
= 4200 J kg^-1K^-1 and the latent heat of
ice = 3.4 $$ \times $$ 10⁵ J kg^–1. 100 grams of ice at
0^oC is placed in 200 g of water at 25^oC. The
amount of ice that will melt as the temperature
of water reaches 0^oC is close to (in grams) :