MODEL PAPER 2025 — Physics STD 12 Science — Question

In the given figure, when galvanometer shows no deflection, the current (in ampere) flowing through 5Ω  resistance will be

(a) 0.5

(b) 0.6

(c) 0.9

(d) 1.5

Mark the incorrect statement.

The coil is wound on an iron core and looped back on itself so that core has two sets of closely wound coils carrying current in opposite directions. The self inductance is.

The magnetic moment of a steel rod of length 'l' is M. It is bent into a semi-circle. The new magnetic moment is :

Let n_r and n_b be the number of photons emitted by a red bulb and a blue bulb, respectively, of equal power in a given time:

A piece of wood is taken deep inside a long column of water and released. It will move up:

1. With a constant upward acceleration.
2. With a decreasing upward acceleration.
3. With a deceleration.
4. With a uniform velocity.

What is the respective number of α and β  particles emitted in the following radioactive decay

(a) 6 and 8

(b) 8 and 8

(c) 6 and 6

(d) 8 and 6

The maximum distance upto which TV transmission from a TV tower of height h can be received is proportional to

(a) h1/2

(b) h

(c) h3/2

(d) h2

Three right angled prisms of refractive indices  and  are fixed together using an optical glue as shown in figure. If a ray passes through the prisms without suffering any deviation, then

(a)	(b)
(c)	(d) 1 +

The wavelength of Lyman series is

(a)

(b)

(c)

(d)