List of practice Questions

For the reactions: NaBH$_4$ + I$_2$ $\rightarrow$ A + NaI + H$_2$, and A + LiH $\rightarrow$ B, what are A and B, respectively? (Reactions are not balanced)
The buffer system that helps in maintaining pH of blood between 7.26 and 7.42 is
The BOD value of clean water is X. The maximum concentration of cadmium recommended in drinking water is Y. X and Y respectively are
The sum of number of antibonding electrons present in O$_2$, O$_2^+$, O$_2^-$ is:
Observe the following molecules: ClF, SF$_4$, CH$_4$, NH$_3$, XeF$_4$, PCl$_5$. The number of molecules in which the central atom has expanded octet is:
One mole of an ideal gas is contained in a 1 L vessel at T(K) with a pressure of p atm. The vessel is split into two equal parts. What are the pressure and volume in each part?
The ratio of the radii of the nuclei of mass numbers 27 and 64 is:
The waves used for line of sight communication and satellite communication are:
If an electron and a proton enter normally into a uniform magnetic field with equal kinetic energies, then:
If the magnetisation of a material is M and the magnetic field in the material is B, then the magnetic intensity is: ($\mu_0$ = permeability of free space)
The energy stored in a coil of inductance 50 mH carrying a current of 2 A is:
A 100 $\Omega$ resistor, a 50 $\mu$F capacitor and an inductor are connected in series to an ac source of frequency 50 Hz. If the circuit is in resonance, then the impedance of the circuit is:
A 10 $\mu$C charge is placed at the vertex A of an equilateral triangle ABC of side 2 m. The work done in taking another charge $(3 + \sqrt{3})$ $\mu$C from the mid point of BC to the mid point of the side AC is:
If a generator of emf 440 V and internal resistance 400 $\Omega$ is connected to an external resistance of 4000 $\Omega$, then the potential difference across the external resistance is:
The nature of the graph between the temperature in Fahrenheit and Celsius values is:
If the length and the focal length of its objective of an astronomical telescope are L and 8 respectively, then the focal length of its eyepiece is:
Rain is falling vertically with a speed of \( 36\ \mathrm{m/s} \) and a boy is moving on a bicycle with a speed of \( 20\ \mathrm{m/s} \) towards south. The angle with the vertical towards south with which the boy has to hold an umbrella is
An aeroplane flying horizontally with a speed of 720 kmph at an altitude of 490 m drops a bomb when it is just vertically above a target. The horizontal distance between the target and the point where the bomb strikes the ground is
A balloon of mass 'M' is rising up with an acceleration 'a'. In order to triple its acceleration, the fraction of mass to be removed from the balloon is (\( g \) - acceleration due to gravity)
A force of 10 N acts on a body of mass 2 kg in the direction of motion of the body. If the velocity of the body at a time \( t = 0 \) is \( 13\,{ms}^{-1} \), then the velocity of the body at time \( t = 3\,{s} \) is
A body is dropped freely from a height of 8 m from the ground. If the coefficient of restitution between the body and the ground is 0.5, then the maximum height reached by the body after second impact with the ground is
A bomb of mass 12 kg at rest explodes into two pieces of masses 4 kg and 8 kg. If the velocity of 8 kg mass is \( 6\,{ms}^{-1} \), then the kinetic energy of 4 kg mass is
Assertion (A): In the polluted area, Birmingham, black peppered moths were abundant. In the non-polluted area, Dorset, grey forms were abundant.
Reason (R): Natural selection.
Identify the correct option from the following
Ontogeny repeats phylogeny. It was the
Which one of the following is a liquid tumor?