Electric Charges and Fields — Physics STD 12 Science — Question

In Young's double slit experiment the intensity of the maxima is I. If the width of each slit is doubled, the intensity of the maxima will be:

If a 12 pF capacitor is connected to a 50 V battery then the electrostatic energy stored in the capacitor is ___________.

Two parallel plates have equal and opposite charge. When the space between them is evacuated, the electric field between the plates is 2 . When the space is filled with dielectric, the electric field becomes 1 . The dielectric constant of the dielectric material

(a) 1/2

(b) 1

(c) 2

(d) 3

In the arrangement of resistances shown below, the effective resistance between points A and B is

(a) 20 Ω

(b) 30 Ω

(c) 90 Ω

(d) 110 Ω

In a compound microscope magnification will be large, if the focal length of the eye piece is

(a) Large	(b) Smaller
(c) Equal to that of objective	(d) Less than that of objective

A potentiometer consists of a wire of length 4 m and resistance 10 W. It is connected to cell of emf 2 V. The potential difference per unit length of the wire will be

(a) 0.5 V/m

(b) 10 V/m

(c) 2 V/m

(d) 5 V/m

The magnetic induction in air at a point 1cm away from a long wire that carries a current of 1A, will be

(a)

(b) 2

(c) 3

(d) 4

The capacitance of an air filled parallel plate capacitor is 10μμF . The separation between the plates is doubled and the space between the plates is then filled with wax giving the capacitance a new value of 40. The dielectric constant of wax is

(a) 12.0

(b) 10.0

(c) 8.0

(d) 4.2

An achromatic prism is made by combining two prisms   and ; where μ  represents the refractive index. If the angle of the prism   is 10°,  then the angle of the prism P₂ will be

(a) 5°

(b) 7.8°

(c) 10.6°

(d) 20°

In a fission reaction , the binding energy per nucleon of X and Y is 8.5 MeV whereas of  is 7.6 MeV. The total energy liberated will be about

(a) 200 KeV

(b) 2 MeV

(c) 200 MeV

(d) 2000 MeV