Explore topic-wise InterviewSolutions in Current Affairs.

The correct option: (c) I only

(c) In the position of minimum deviation i =e=A+δM /2 =60+30/2=45^o

(d) violet colour

(a) Violet innermost, red outermost.

(a) In the position of minimum deviation, i₁ = i₂ .

 (c) The ratio of the sine of the angle of incidence to the sine of angle of refraction is constant. Remember that the angles of incidence (i) and refraction (r) are the angles that the incident and its refracted ray make with the normal, respectively. We have, sin i/sin r =n₂₁ ...(i) where, n₂₁ is a constant, called the refractive index of the medium 2 w.r.t. the medium 1. Eq. (i) is the well known Snell’s law of refraction. We note that n₂₁ is a characteristic of the pair of media (and also depends on the wavelength of light) but is independent of the angle of incidence 

(b) Red innermost, violet outer most.

(b) Frequency does not change on refraction

EXPLANATION:   

When light is refracted into a medium its speed changes but the frequency remains the same because the energy associated with a photon of this light is proportional to the frequency of the light and it remains unchanged. Since the wavelength λ = c/, i.e. λ ∝ c. So the wavelength changes. Option (c) is true.

(b) Normal is perpendicular to the tangent to surface at the point of incidence i.e., the normal is along the radius, the line joining the centre of curvature of the mirror to the point of incidence. So, geometric centre of a spherical mirror is called its pole while that of a spherical lens is called its optical centre. The line joining the pole and the centre of curvature of the spherical mirror is known as the principal axis. In the case of spherical lenses, the pricipal axis is the line joining the optical centre with its principal focus.

Chromatic aberration in a lens is caused by

(d) dispersion

\(\frac1{\lambda}=R(\frac1{n_1^2}-\frac1{n_2^2})\) R → Rydburg constant

Balmer series

n₁ = 2

n₂ = \(\infty\)

for highest energy n₂ → \(\infty\) 

\(\frac1{\lambda_B}=R(\frac1{2^2}-\frac1{\infty})\) 

\(\frac1{\lambda_B}=R(\frac1{4})\) 

\(\frac1{\lambda_B}=R(\frac R{4})\) 

\({\lambda_B}=\frac4{R}\) 

for paschen series n₁ = 3, n₂ = \(\infty\)

\(\frac1{\lambda_p}=R(\frac{1}{(3^2)}-\frac1{(\infty^2)})\) 

\(\frac1{\lambda_p}=\frac{R}{p}\) 

\(\lambda_p=\frac{q}R,\) 

 \(\frac{\lambda_b}{\lambda_p}=\cfrac{\frac4R}{\frac{q}R}\) 

⇒  \(\frac4R\times\frac{R}q\)

⇒ 4 : q

Given \(E = 4 \times 10^{-19} J\)

Frequency \(V =\, ?\)

\(E = hV\)

\(V = \frac Eh\)

\(V = \frac{4\times 10^{-19}}{6.64 \times 10^{-34}}\)

\(V = 0.602 \times 10^{15}\)

\(V = 6.02 \times 10^{14} Hz\)

Adulteration in food product causes malnutrition.  

Laundry is an art and science - It is science as it is based on application of scientific principles and techniques.

It is art since application requires the mastering of certain skills to produce aesthetically pleasing results. Any other 

Four differences between household and commercial laundry

To save clothes from insects Newspaper's ink, Naphthalene balls, Dried neem leaves are applied.   

Blue is applied to white clothes because-

It acts as a fabric whitener/brightener

Four steps of applying blue to the clothes-

1.Add blue to water and dissolve well 

2.Wet the article to be blued in water and squeezed properly 

3.The article is opened and then dipped in the above blue solution

4.The article is squeezed and put in the sun

OR

Starch is applied to clothes because-

It gives crispness/stiffness/brightness to the fabric

Four steps of applying starch to the clothes-

1.Mix starch paste in water and dissolve well

2.Wet the article to be starched in water, squeeze it properly 

3.Open the article and dip in starch solution 

4.Squeeze and spread in the sun

Four ways to create variety are-

1. Selection of foods from different food groups 

2. Variety in color combination Blending of different colors makes food attractive, eye appealing and also enhances appetite. 

3. Variety in texture

The Texture in food refers to its softness, crispness and the solid or liquid state of the food.

4. Variety in taste and flavor A meal will tempt only if it has variety of flavor and aroma. 

5. Any other

Four ways to save time and money

1. Once the meals are planned, prepare a list of items and they can be purchased together.

2. Ingredients in bulk quantities cost less but should be purchased only when there is proper

Provision for its storage.

3. Purchasing should be made at time periods when the markets are not very crowded.

4. Labor saving kitchen devices like mixer, fridge, pressure cooker, etc. should be used.

5. Any other

(i) a. Should be destarched and dried in air

(ii) c. Mildew

(iii) a. Vinegar

(iv) a. Silver fish

Six ways to remain careful so that fruit vendor does not cheat while weighing the fruits-

1. Hollow bottom iron weights should not be used 

2. Check magnet should not be there under the pan of the weighing scale 

3. Pointers must be there in weighing scale 

4. Vendor should not use irregular weights 

5. Iron rings should not be hung on one side of weighing scale 

6. Weighing balance must remain horizontal

a) Cotton shirt should be de -starched before storing-

As starched clothes can be attacked by silverfish 

b) Food stains should be immediately removed from woollen sweater-

As micro-organisms attack any food stain

a) Four points to be kept in mind while planning menu for 15- year-old boy-

1. Menu should be nutritious 

2. Easy to eat 

3. Avoid over eating and dieting 

4. Food should provide satiety

b) Two ways of preparing a low-cost meal- 

1. Prefer using seasonal fruits and vegetables 

2. Substitute expensive food with low-cost nutritious food-For example use peanuts instead almonds 

3. Use locally available food products