An astronomical telescope has a large aperture to

Two solenoids of equal number of turns having their lengths and radii in the same ratio \(1: 3\). The ratio of their self inductances \(L _{ 1 }: L _{ 2 }\) will be :

The shortest wavelength in the Balmer series of hydrogen atom would be (Given R = \( 1.1 \times 10^7 \, m^{-1} \))

The velocity of an EM wave in a given medium is \( \vec{V} = 3 \times 10^8 \hat{j} \). When electric field oscillates along z-axis, then direction of oscillation of magnetic field at that time should be :

The half life of a radioactive isotope of Iodine 131 is 8 days. Starting with 64 mg of the Iodine 131, the amount that disintegrates in 24 days is :

Two point changes \( - q \) and \( + q \) are located at points \( (0, 0, -a) \) and \( (0, 0, +a) \) respectively. The electric potential of a point \( (0, b, 0) \), where \( b > a \), is :

In an inductive circuit, the current falls from 7.5 A to 1.5 A in 0.15 s. It induces emf of 220 V in the inductive coil. The inductance of the circuit is

Read the following passage carefully and answer the given questions.
Productivity in the Ecosystem The flow of energy through a terrestrial ecosystem starts with the harnessing of sunlight by autotrophs. The radiant energy is converted by photosynthesis to organic compounds is known as productivity. The productivity is expressed in units of energy per unit of area per unit time. The amount of organic matter present at any given time is biomass. The productivity of any ecosystem is affected by many parameters like weather conditions, nutrient availability etc. The productivity of any ecosystem does vary seasonally and yearly.
The Net Primary Productivity of an ecosystem are represented by:

What is the full form of ELISA ?

Identify the carbohydrate which is not a polysaccharide

Which of the following is the wrong statement? Coulomb's law describes the electric force that

A system has two charges, \( q_A = 5 \times 10^{-7} \, \text{C} \) and \( q_B = -5 \times 10^{-7} \, \text{C} \), located at points \( A : (0, 0, -10 \, \text{cm}) \) and \( B : (0, 0, +10 \, \text{cm}) \), respectively. Which of the following are true?
(A) The electric field of dipole at point (0, 0, -15 cm) is \( 1.73 \times 10^6 \, \text{NC}^{-1} \)
(B) Electric field intensity is zero at origin (0, 0, 0)
(C) dipole moment \( (p) = 5 \times 10^{-8} \, \text{C-m} \)
(D) direction of the dipole moment is along the negative z- axis
Choose the correct answer from the options given below:

The rate of a gaseous reaction becomes half when the volume of the vessel is doubled. The order of the reaction is