List of practice Questions

If for z=α+iβ, |z+2|=z+4(1+i), then α +β and αβ are the roots of the equation

For two groups of 15 sizes each, mean and variance of first group is 12, 14 respectively, and second group has mean 14 and variance of σ2. If combined variance is 13 then find variance of second group?

The ratio of magnetic field due to coil at centre and at distance of R from the centre on the axis passing through the centre and perpendicular to the plane of ring is : 1x (R is the radius of coil), find the value of x.
In an ice crystal, each water molecule is hydrogen bonded to ___ neighbouring molecules
A steel rod of length 1 m and cross sectional area 10-4 m² is heated from 0°C to 200°C without being allowed to extend or bend. The compressive tension produced in the rod is______ ×104N. (Given Young's modulus of steel = 2×1011 Nm-2, coefficient of linear expansion = 10-5K-1)
The number of colloidal systems from the following, which will have 'liquid' as the dispersion medium, is____.
Gem stones, paints, smoke, cheese, milk, hair cream, insecticide sprays, froth, soap lather.
A hollow spherical ball of uniform density rolls up a curved surface with an initial velocity 3 m/s (as shown in figure). Maximum height with respect to the initial position covered by it will be_____ cm (take, g = 10 m/s²)
A hollow spherical ball of uniform density
The number density of free electrons in copper is nearly 8 × 1028 m-3. A copper wire has its area of cross section = 2 × 10-6 m² and is carrying a current of 3.2 A. The drift speed of the electrons is _____ ×10-6 ms-1
A series combination of resistor of resistance 100 Ω, inductor of inductance 1 H and capacitor of capacitance 6.25 µF is connected to an ac source. The quality factor of the circuit will be ______
Consider the following date
Heat of combustion of H2(g)           = -241.8 kJ mol-1 
Heat of combustion of C(s)              = -393.5 kJ mol-1 
Heat of combustion of C2H5OH(1)  = -1234.7 kJ mol-1
The heat of formation of C2H5OH(1) is (-) ____ kJ mol-1 (Nearest integer)

A body of mass \( (5 \pm 0.5) \, \text{kg} \) is moving with a velocity of \( (20 \pm 0.4) \, \text{m/s} \). Its kinetic energy will be:

A 600 pF capacitor is charged by 200 V supply. It is then disconnected from the supply and is connected to another uncharged 600 pF capacitor. Electrostatic energy lost in the process is _____ μ.J
The number of species having a square planar shape from the following is __
\(XeF_4, SF_4, SiF_4, BF^-_4 BrF^-_4,[Cu(NH_3)_4]^{2+}, [FeCl_4]^{2-}, [PtCl_4]^{2-}\)
Number of crystal systems from the following where body centred unit cell can be found, is......
Cubic, tetragonal, orthorhombic, hexagonal, rhombohedral, monoclinic, triclinic.
In photo electric effect
A. The photocurrent is proportional to the intensity of the incident radiation.
B. Maximum Kinetic energy with which photoelectrons are emitted depends on the intensity of incident light.
C. Max. K.E with which photoelectrons are emitted depends on the frequency of incident light.
D. The emission of photoelectrons require a minimum threshold intensity of incident radiation.
E. Max. K.E of the photoelectrons is independent of the frequency of the incident light.
Choose the correct answer from the options given below:
Given below are two statements :
Statement-I: Morphine is a narcotic analgesis. It helps in relieving pain without producing sleep. 
Statement-II: Morphine and its derivatives are obtained from opium poppy. 
In the light of the above statements, choose the correct answer from the options given below.
Match the terms in Column-I with their description in Column-II and choose the correct option:
 Amino Acid Letter Code
(A).Alanine(P).N
(B).Asparagine(Q).A
(C).Aspartic acid(R).R
(D).Arginine(S).D
The strongest acid from the following is

The equivalent resistance between \( A \) and \( B \) as shown in the figure is:
The equivalent resistance between

Find out the major product from the following reaction.
major product from the following reaction jee main 2023

An engine operating between the boiling and freezing points of water will have 
A. efficiency more than 27%  
B. efficiency less than the efficiency a Carnot engine operating between the same two temperatures.  
C. efficiency equal to 27%  
D. efficiency less than 27% 

A radio active material is reduced to 1/8 of its original amount in 3 days.
If 8×10-3 kg of the material is left after 5 days the initial amount of the material is
In the following reaction 'B' is
In the following reaction 'B' is jee main 2023
For particle P revolving round the centre O with radius of circular path r and angular velocity ω, as shown in below figure, the projection of OP on the x-axis at time t is
For particle P revolving round the centre O
During the detection of Lead, the Formation of which of the following compounds is not used as a confirmatory test.