A message signal of peak voltage 20 V is used to modulate a carrier wave of amplitude 40 V in amplitude modulation. The ratio of maximum amplitude and minimum amplitude in amplitude modulated signal is:

A square coil of side 10 cm, 500 turns and resistance 3 \(\Omega\) is placed with its plane perpendicular to the horizontal component of the Earth's magnetic field. It is rotated about vertical axis passing through centre by 180° in 0.25 second. Estimate the magnitude of the emf and current induced in the coil. Horizontal component of the Earth's magnetic field at the place is 3.0 \(\times 10^{-5}\) T.

Which of the following are not electromagnetic waves?
A. Gamma rays
B. Cathode rays
C. X-rays
D. \(\beta\)-rays
E. Radio waves
Choose the correct answer from the options given below:

The cause of the depletion layer in the p-n junction region is

Which of the following statements are correct?
(A) Metals obey Ohms law at constant temperature.
(B) The resistivity of the metals depends on temperature.
(C) The conductivity of the metals is independent of temperature.
(D) The number of electrons per unit volume in a metal is independent of temperature.
Choose the correct answer from the options given below:

The resistance of the platinum wire of a platinum resistance thermometer at the ice point is 5 \(\Omega\) and at steam point, it is 5.23 \(\Omega\). When the thermometer is inserted in a hot bath, the resistance of the platinum wire becomes 5.795 \(\Omega\). Find the temperature of the bath.

Three charges of magnitude \( -2Q, -3Q \) and \( Q \) are located at \( (a, 0, 0), (3a, 0, 0) \) and \( (5a, 0, 0) \) respectively. What is the magnitude of electric flux due to these charges through a sphere of radius 4a with its centre at the origin?

The correct decreasing order of acidic strengths of trioxides of nitrogen family is
A. \(\text{P}_2\text{O}_3\)
B. \(\text{N}_2\text{O}_3\)
C. \(\text{As}_2\text{O}_3\)
D. \(\text{Bi}_2\text{O}_3\)
E. \(\text{Sb}_2\text{O}_3\)
Choose the correct answer from the options given below:

The shortest distance between lines \(\frac{-x-3}{4}=\frac{y-6}{3}=\frac{z}{2}\) and \(\frac{-x-2}{4}=\frac{y}{1}=\frac{z-7}{1}\) is :

In the month of January, the number of cases diagnosed of influenza epidemic are given in the following table:

Date	1	2	3	4	5	6	7
Number of cases	2	0	5	12	20	27	46

The 3-day moving averages are:

Read the passage carefully and answer the questions
Nearly all the transition elements display typical metallic properties such as high tensile strength, ductility, malleability, high thermal and electrical conductivity and metallic lustre. The transition metals (with the exception of Zn, Cd and Hg) are very hard and have low volatility. Their melting and boiling points are high. They have high enthalpies of atomization. lons of the same charge in a given series show progressive decrease in radius with increasing atomic number. However, the variation within a series is quite small. The filling of 4f before 5d orbital results in a regular decrease in atomic radii called Lanthanoid contraction which essentially compensates for the expected increase in atomic size with increasing atomic number. The net result of the lanthanoid contraction is that the second and the third d series exhibit similar radii (e.g., Zr 160 pm, Hf 159 pm) and have very similar physical and chemical properties. There is an increase in ionisation enthalpy along each series of the transition elements from left to right. The first ionisation enthalpy, in general, increases, but the magnitude of the increase in the second and third ionisation enthalpies for the successive elements, is much higher along a series. One of the notable features of a transition elements is the great variety of oxidation states these may show in their compounds.
Atomic number of \(\mathrm{V}, \mathrm{Mn}, \mathrm{Cu}\) and Zn is \(23,25,29\) and 30 respectively. Which of them shows a positive value for the standard electrode potential \(E^{\circ}\left(M^{2+} / M\right)\) ?

Let \(M_{i j}\) and \(A_{i j}\) denote respectively minors and co-factors of the element in the ith row and jth column of the matrix \(A=\left[\begin{array}{ccc}1 & 2 & -1 \\ 3 & 2 & 3 \\ 4 & -1 & 0\end{array}\right]\). Then
(A) \(M_{32}=6\)
(B) \(M_{23}=9\)
(C) \(A_{32}=-6\)
\((D) A_{23}=-9\)
Choose the correct answer from the options given below :

Apomixis is the -