Nuclei — Physics STD 12 Science — Question

A wire of resistance R is divided in 10 equal parts. These parts are connected in parallel, the equivalent resistance of such connection will be

(a) 0.01 R

(b) 0.1 R

(c) 10 R

(d) 100 R

Two thin lenses whose powers are +2D and –4D respectively combine, then the power of combination is

(a) – 2D

(b) + 2D

(c) – 4D

(d) + 4D

There is a uniform electric field of strength   along y-axis. A body of mass 1g and charge is projected into the field from origin along the positive x-axis with a velocity 10m/s. Its speed in m/s after 10s is (Neglect gravitation)

(a) 10

(b) 5

(c) 10

(d) 20

A parallel plate capacitor is first charged and then isolated, and a dielectric slab is introduced between the plates. The quantity that remains unchanged is:

Which of the following effects could not be explained by Maxwell's electromagnetic wave theory?

The dependence of drift velocity on applied electric field E is:

A bar magnet is situated on a table along east-west direction in the magnetic field of earth. The number of neutral points, where the magnetic field is zero, are

(a) 2

(b) 0

(c) 1

(d) 4

Speed of electromagnetic waves in vacuum is:

Electromagnetic waves are produced by: