List of practice Questions

The count rate of a Geiger Muller counter for the radiation of a radioactive material of half-life of 30 minutes decreases to 5 second$^{-1}$ after 2 hours. The initial count rate was
The percentage weight of Zn in white vitriol $[ZnSO_4 . 7H_2O]$ is approximately equal to $(at. \, mass\, of \, Zn= 65, S=32, 0=16 \, and \, H= 1)$
Stainless steel contains iron and
A star, which is emitting radiation at a wavelength of $5000$ $�$ is approaching the earth with a velocity of $1.5 \times 10^4m/s.$ The change in wavelength of the radiation as received on the earth is
The earth (mass = $ 6 \times {10}^{24} $ kg) revolves around the sun with an angular velocity of $ 2 \times {10}^{-7} rad/s$ in a circular orbit of radius $ 1.5 \times {10}^8 km$. The force exerted by the sun on the earth, in newton, is
The loss of electron is termed as
The number of geometrical isomers for [Pt(NH3)2Cl2] is
The oxidation number of chromium in potassium dichromate is
Antigens are present
In veins, valves are present to check backward flow of blood flowing at
The transgenic animals are those which have
The organisms attached to the substratum, generally, possess
The sympathetic nerves, in mammals, arise from
The vitamin C or ascorbic acid prevents
The silkworm silk is the product of
Respiratory quotient (R.) for fatty acid is
The plant body of moss (Funaria) is
A well developed archegonium with neck consisting of 4-6 rows and neck canal cells, characterises
Anthesis is a phenomenon which refers to
Which of the following can fix atmospheric nitrogen ?
The number of moles of oxygen in 1 L of air containing 21% oxygen by volume, under standard conditions, is
Heat is flowing through two cylindrical rods of the same material. The diameters of the rods are in the ratio 1 : 2 and the lengths in the ratio 2 : 1. If the temperature difference between the ends is same, then ratio of the rate of flow of heat through them will be
The acceleration of a particle is increasing linearly with time $t$ as $bt$. The particle starts from origin with an initial velocity $v_0$. The distance travelled by the particle in time t will be
The dimensions of pressure are same as that of
The radius of hydrogen atom in the ground state is 0.53 $\mathring{A}.$ The radius of $Li^{2+}$ ion (at. no. = 3) in a similar state is