Magnetism And Matter — Physics STD 12 Science — Question

A conducting rod of length l is falling with a velocity v perpendicular to a uniform horizontal magnetic field B. The potential difference between its two ends will be

(a) 2Blv

(b) Blv

(c)

(d)

The resistance of a metal increases with increasing temperature because:

The susceptibility of paramagnetic substance is :

Frequency and potential difference of AC sent to homes in India is:

The image distance of an object placed 10 cm in front of a thin lens of focal length + 5 cm is

(a) 6.5 cm

(b) 8.0 cm

(c) 9.5 cm

(d) 10.0 cm

A beam of light AO is incident on a glass slab (μ = 1.54)  in a direction as shown in figure. The reflected ray OB is passed through a Nicol prism on viewing through a Nicole prism, we find on rotating the prism that

(a) The intensity is reduced down to zero and remains zero

(b) The intensity reduces down some what and rises again

(c) There is no change in intensity

(d) The intensity gradually reduces to zero and then again increases

Which among the following can be used to analyze circuits?

The variation of decay rate of two radioactive samples A and B with time is shown in Fig. Which of the following statements are true?

When the current i is flowing through a conductor, the drift velocity is v. If  2i  current is flowed through the same metal but having double the area of cross-section, then the drift velocity will be

(a) v/4

(b) v/2

(c) v

(d) 4v

Consider the situation of the previous problem. The directions of the magnetic field due to the dipole are opposite at: