Two thin lenses of focal lengths \( f_1 \) and \( f_2 \) are in contact and coaxial. The power of the combination is:

Two sources are producing waves as given in the options below. Which two sources are called coherent ?

If light of wavelength 412.5 nm is incident on each of the metals given below, which ones will show photoelectric emission ?

Metal	Work Function (eV)
Na	1.92
K	2.15
Ca	3.20
Mo	4.17

Choose the correct answer from the options given below:

Match List I with List - II.

List I	List II
(A) Zener diode	(I) operates under forward bias
(B) LED	(II) operates under reverse bias
(C) Solar cell	(III) operates under reverse bias in break down region
(D) Photo diode	(IV) no biasing is applied

Choose the correct answer from the options given below :

A ray is incident normally on the face of an equilateral prism of refracting angle \(60^{\circ}\).
The refractive index of the prism is \(\frac{2}{\sqrt{3}}\).
The angle of deviation will be:

In the given figure, the ratio of electric fluxes through surfaces \( S_1 \) and \( S_2 \) is

Identify the correct statement(s) from the following Resistivity (\( \rho \)) versus Temperature (T) graphs :

(A) Graph (i), shows \(\rho\) versus \(T\) variation for Copper
(B) Graph (ii), shows \(\rho\) versus \(T\) variation for Silicon
(C) Graph (iii), shows \(\rho\) versus \(T\) variation for semiconductor
(D) Graph (iii), shows \(\rho\) versus T variation for Nichrome
Choose the correct answer from the options given below :

Match List-I with List-II

List-I (Solute)	List-II (Van't Hoff factor)
(A) Benzoic acid in benzene	(I) 3
(B) \(K _2 SO _4( aq )\)	(II) 2
(C) Urea (aq)	(III) 0.5
(D) \(KOH ( aq )\)	(IV) 1

Choose the correct answer from the options given below:

In Young's double slit experiment, two slits are made 4 mm apart and the screen is placed 3 m away from slits. The fringe width when light of wavelength 600 nm is used will be:

The phase difference between two points A and B on a given wavefront separated by distance \(\lambda\) is :

Read the passage carefully and answer
Carbohydrates are essential for both plants and animals. Some common examples of carbohydrates are glucose, fructose, sucrose, glycogen, cellulose and starch. They form a major portion of our food. Honey has been used for a long time as an instant source of energy in Ayurvedic medicine. Carbohydrates are used as storage molecules in both plants and animals. The cell wall of bacteria and plants is made of cellulose. We use cellulose in the form of wood for making furniture and as cotton fiber for clothing. They also provide raw material for textiles, paper, lacquers, and breweries. Carbohydrates are classified as Monosaccharides, Oligosaccharides and Polysaccharides on the basis of their behavior towards hydrolysis.
Monosaccharides cannot be hydrolyzed further to simpler units whereas oligosaccharides can yield 2-10 units of monosaccharides on hydrolysis. Polysaccharides, which are non-sugars yield a large number of monosaccharide units on hydrolysis.
Answer the following questions about carbohydrates:
Identify a component of starch from among the following.

Genes which code for a pair of contrasting traits are knows as:

A body oscillate with SHM according to equation (SI unit),
\( x = 10 \cos(2\pi t + \pi/4) \)
at t= 1.5 s, calculate the speed of the body.