Question

Std :- XII-Sci UNIT TESTOT Time :- SUB :- PHYSICS Mark :- 25 2.1 a ii ) d) power 60 IT 30 SEC-A Select and write the correct answer i) The ratio of maximum to minimum intensities in a interference pattern is 25 : 1. The ratio of the amplitudes of the two waves is a) 3:2 b) 2:3 c) 5:1 d) 1:5 L2 represents 21 a) Rotational kinetic energy of a particle b) potential energy of a particle c) torque on a particle iii) The angular velocity of second hand in a clock is a) rad's b) 2 rad/s c) i rad s d) -rad/s iv) Huygen'S wave theory of light could not explain a) reflection b) refraction c) interference d) photoelectric effect Answer the following i) If distance between source and point of observation is infinite then formed wave-front will be. ii) The ratio of total energies of a particle performing vertical circular motion at the top and the bottom is ? iii) State condition to get constructive and destructive interference pattern. SEC-B Attempt any FOUR Define moment of inertia. Explain the physical significance of it 3 2.2 N 0.3​

Answer 1

Answer:

$5 \time. \\ .2 \beta \beta bgvfyubji \sec(?) 333.3..3 {.}^{?..4. \tan( \tan( \t \tan( \cot( \beta ) ) an( \cos(?) ) ) ) } 3s \frac = = = ..{?}{?} log(?)$

Answer 2

Answer:

Explanation:

write the correct answer i) The ratio of maximum to minimum intensities in a interference pattern is 25 : 1. The ratio of the amplitudes of the two waves is a) 3:2 b) 2:3 c) 5:1 d) 1:5

Answer

$\frac{Imax}{Imin} =\frac{25}{1}$

⇒$\frac{(a+b)^{2} }{(a-b){2} }$ = $\frac{25}{1}$

⇒ $\frac{a+b}{a-b} =\frac{5}{1}$

⇒ a+b=5a-5b

⇒4a = 6b ⇒$\frac{a}{b}$    =  $\frac{6}{4}$  $\frac{3}{2}$

a:b= 3:2

Option a) is correct

L^2/2I represent

a) Rotational kinetic energy of a particle

b) potential energy of a particle

c) torque on a particle

Answer:

L =Iω

$\frac{L^{2} }{2I} = \frac{I^{2} w^{2} }{2I} = \frac{1}{2}Iw^{2}$

$\frac{1}{2} Iw^{2}$ is  a rotational kinetic energy

Therefore ,$\frac{L^{2} }{2I}$ is rotational kinetic energy of the particle

Option a) is correct

iii) The angular velocity of second hand in a clock is a) rad's b) 2 rad/s c) i rad s d) -rad/s

Answer:

second of the clock complete one turn in one sec i,e 1 revolution per minute

Angular velocity of seconds hand

ω = 2π/60

π/30

rad/s

Option d) is correct

iv) Huygen'S wave theory of light could not explain a) reflection b) refraction c) interference d)photoelectric effect

Answer:

Huygens  wave theory of light cannot explain the photoelectric effect. Because it is due to particle nature of light

Option d) is correct

i) If distance between source and point of observation is infinite then formed wave-front will be

Plane wavefront

ii) The ratio of total energies of a particle performing vertical circular motion at the top and the bottom is ?

iii) State condition to get constructive and destructive interference pattern.

The condition for constructive interference is that the phase difference between the two waves should be an even integral multiple of π or 180° . for destructive interference , the phase difference between the two waves is an odd integral multiple of π or 180° .

B Attempt any FOUR Define moment of inertia.

inertia is defined as a property of matter by which it remains at the state of rest or in uniform motion in the same straight line unless acted upon by some external force ,inertia is an object inherent property to avoid  a transition in its state of action or rest .an object mass is a measure of its inertia.

Explain the physical significance of it 3 2.2 N 0.3​

Physical significance:

The physical significance of moment of inertia is similar to the mass in translational motion. in similar to the mass in translational motion, the mass of a body is used for measuring inertia. as the mass increase , inertia measuring inertia.