Electric Charges and Fields — Physics STD 12 Science — Question

If in a nuclear fission, piece of uranium of mass 0.5 g is lost, the energy obtained in kWh is

(a) 1.25

(b) 2.25

(c) 3.25

(d) 0.25

Hysterisis is the phenomenon of lagging of:

The critical angle between an equilateral prism and air is 45°. If the incident ray is perpendicular to the refracting surface, then

(a) After deviation it will emerge from the second refracting surface

(b) It is totally reflected on the second surface and emerges out perpendicularly from third surface in air

(c) It is totally reflected from the second and third refracting surfaces and finally emerges out from the first surface

(d) It is totally reflected from all the three sides of prism and never emerges out

Identify the material whose resistivity lie between 10^-6 Ωm and 10⁴ Ωm.

A circular loop carrying a current is replaced by an equivalent magnetic dipole. A point on the axis of the loop is

(a) An end-on position	(b) A broad side-on position
(c) Both (a) and (b)	(d) Neither (a) nor (b)

If resistance of a conductor is reduced to half and magnitude of current is doubled, then produced heat:

A convex mirror is used to form the image of an object. Then which of the following statements is wrong

(a) The image lies between the pole and the focus

(b) The image is diminished in size

(c) The image is erect

(d) The image is real

In a parallel plate condenser, the radius of each circular plate is 12 cm  and the distance between the plates is 5mm. There is a glass slab of 3mm  thick and of radius 12 cm  with dielectric constant 6 between its plates. The capacity of the condenser will be

(a) 144

(b) 40 pF

(c) 160 pF

(d) 1.44 μF

The ultimate individual unit of magnetism in any magnet is called

(a) North pole

(b) South pole

(c) Dipole

(d) Quadrupole