List of practice Questions

A 280 day old radioactive substance shows an activity of 6000 dps, 140 days later its activity becomes 3000 dps. What was its initial activity?

Which of the following hormones contains iodine?

Which of the following is not true for $S_N1$ reaction ?

Which of the following is the correct pathway of absorbed water in the roots of plants ?

Which of the following statements is not true for Nostoc ?

X-rays, gamma rays and microwaves travelling in vacuum have

Two thin plano-convex lenses each of focal length $f$ are placed as shown in the figure. The ratio of their effective focal lengths in the three cases is

The value of $^{10}C_1+^{10}C_2+^{10}C_3+....+^{10}C_9 $ is

The $pH$ of the solution obtained by mixing $100\, ml$ of a solution of $pH = 3$ with $400\, ml$ of a solution of $pH = 4$ is

The correct order of electronegativities of $N, O, F$ and $P$ is

Sucrose is NOT a reducing sugar since

Power alcohol is a mixture of

In the loop shown, the magnetic induction at the point $O$ is

If father shows normal genotype and mother shows a carrier trait for haemophilia:

A planet moving around sun sweeps area $A_1$ in $2$ days, $A_2$ in $3$ days and $A_3$ in $6$ days. Then the relation between $A_1, A_2 $ and $A_3$ is

When a mass is rotating in a plane about a fixed point, its angular momentum is directed along

The common bottle cork is a product of

If $v_e$ is escape velocity and $v _o$ is orbital velocity of a satellite for orbit close to the earth's suface, then these are related by

A car of mass m starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude $P_0$. The instantaneous velocity of this car is proportional to

Earthworms have no skeleton but during burrowing, the anterior end becomes turgid and acts as a hydraulic skeleton. It is due to

Let R be the set of real numbers A = {(x, y) $\in$ R $\times$ R : y - x is an integer} is an equivalence relation on R. B = {(x, y) $\in$ R $\times$ R : x = $\alpha$y for some rational number $\alpha$} is an equivalence relation on R.

Let $f (x)$ and $g(x)$ be differentiable functions on (0, 2] such that $f"(x) - g"(x) = 0, f'(1) = 2g'(1) = 4, f(2) = 3g(2) = 9.$ Then $f (x)- g(x)$ at $ x = 3/2$ is

If $f\left(x\right) = \frac{x^{2} -1}{x^{2} +1} ,x\in R$ then the minimum value of $f$ is

If the area of a circle increases at a uniform rate, then its perimeter varies