Atoms — Physics STD 12 Science — Question

Electric flux per unit solid angle is defined as:

The current flowing in a coil of self inductance 0.4 mH is increased by 250 mA in 0.1 sec. The e.m.f. induced will be

(a) + 1 V

(b) – 1 V

(c) + 1 mV

(d) – 1 mV

Field lines start from____ charges and ends at _____ charges.

A long, straight wire carries a current along the z-axis, One can find two points in the x−yplane such that:

A convex lens of focal length 12 cm is made of glass of μ = . What will be its focal length when immersed in liquid of μ =  

(a) 6 cm

(b) 12 cm

(c) 24 cm

(d) 30 cm

 has half life 5700 years. At the end of 11400 years, the actual amount left is

(a) 0.5 of original amount	(b) 0.25 of original amount
(c) 0.125 of original amount	(d) 0.0625 of original amount

The magnitude of magnifying power of an astronomical telescope is 5, the focal power of its eyepiece is 10 diopters. The focal power of its objective (in diopters) is:

The color coding of  earth, live and neutral wire respectively is:

Mass of atom expressed in atomic mass unit is:

Thermal neutrons can cause fission in

(a)

(b)

(c)

(d)