List of practice Questions

The length of a seconds pendulum at a height h=2R from earth surface will be :
(Given : R= Radius of earth and acceleration due to gravity at the surface of earth g=π2ms−2)
A hydrogen-like atom of atomic number Z transits from n=4 to n=3. The photon emitted from this transition is incident on a metal surface of threshold wavelength λth = 310nm. If the maximum kinetic energy of the emitted electron is 1.95ev, find the value of Z.

For a free body diagram shown in the figure, the four forces are applied in the ' $x$ ' and ' $y$ ' directions What additional force must be applied and at what angle with positive $x$-axis so that the net acceleration of body is zero?

A block of mass 100 gm is placed on a smooth surface, moves with the acceleration of a=2x, the change in kinetic energy can be given as \((\frac {x^n}{10})\), find the value of n.

Choose the correct option. 
major product
Let the area enclosed by the $x$-axis, and the tangent and normal drawn to the curve $4 x^3-3 x y^2+6 x^2-5 x y-8 y^2+9 x+14=0$ at the point $(-2,3)$ be $A$. Then $8 A$ is equal to ______
Let $S$ be the set of all $a \in N$ such that the area of the triangle formed by the tangent at the point $P ( b, c), b, c \in N$, on the parabola $y^2=2$ ax and the lines $x=b, y=0$ is $16$ unit ${ }^2$, then $\displaystyle\sum_{a \in S} a$ is equal to _____

What is the major product of the following reaction?

 

Separation between earth and sun is given by 1.5 × 106 km. Time period of another planet is 2.83 year. Find distance of another planet from sun?

The reaction between napthalene and chromium trioxide in the presence of glacial acetic yields:
Basic dyes are used in microbiological staining. Which of the following statement is wrong about mechanism of staining?
In a radioactive decay process, the activity is defined as A = - \(\frac {dN}{dt}\), where 𝑁(𝑡) is the number of radioactive nuclei at time 𝑡. Two radioactive sources, 𝑆1 and 𝑆2 have same activity at time 𝑡 = 0. At a later time, the activities of 𝑆1 and 𝑆2 are 𝐴1 and 𝐴2, respectively. When 𝑆1 and 𝑆2 have just completed their 3rd and 7th half-lives, respectively, the ratio \(\frac{A_1}{A_2}\) is _________.
If de-Broglie wavelength is \(\lambda\) when energy is E. Find the wavelength at \(\frac{E}{4}\) (Kinetic Energy).
Five jumbled up sentences (labelled 1, 2, 3, 4 and 5), related to a topic, are given below. Four of them can be put together to form a coherent paragraph. Identify the odd sentence and key in the number of that sentence as your answer.

The temperature of the body drops from 60°C to 40°C in 7 min. The surrounding temperature is 10°C. The temperature of the body drops from 40°C to T°C in 7 min. Find the value of T

1 kilobyte is equal to
In a right-angled triangle Δ ABC , the altitude AB is 5 cm , and the base BC is 12 cm . P and Q are two points on BC such that the areas of ΔABP, ΔABQ , and Δ ABC are in arithmetic progression. If the area of Δ ABC is 1.5 times the area of Δ ABP , the length of PQ , in cm , is
Let C be the circle in the complex plane with centre z0 =\(\frac{1}{2}\) (1+3i) and radius r = 1. Let z1 = 1+ i and the complex number z2 be outside the circle C such that |z1 – z0| |z2 – z0| = 1. If z0, z1 and z2 are collinear, then the smaller value of |z2|2 is equal to
Let $a _{ n }=\int\limits_{-1}^{ n }\left(1+\frac{ x }{2}+\frac{ x ^2}{2}+\frac{ x ^3}{3}+\ldots \ldots +\frac{ x ^{ n -1}}{ n }\right) dx$ for $n \in N$ Then the sum of all the elements of the set $\left\{ n \in N : a _{ n } \in(2,30)\right\}$ is ______
Who is the primary source of information for doctors’ prescribing behaviour?
The coefficient of x and x\(^2\) in (1 + x)\(^p\) (1 – x)\(^q\) are 4 and – 5, then 2p + 3q is
The major product of the reaction is
BrCH2 CO2Et, Zn
The major product in the following reaction is
NaH Raney-Ni/H2
The most stable conformation of Y and that of Z are
stable conformation-Bu Y
The major product Y in the following reaction scheme is
HBr an organic salt