List of practice Questions

0 .15 g of a substance dissolved in 15 g of a solvent higher by 0.216$^\circ$C than that of the pure solvent. Find out the molecular weight of the substance. $(K_b\, for\, solvent \, is\, 2.16 ^\circ C)$
The number of atoms in 4.25 g of $NH_3$ is approximately
The oxidation number of phosphorus in pyrophosphoric acid is
The de-Broglie wavelength of a particle with mass 1 g and velocity 100 m/s is
Who modified Bohr's theory by introducing elliptical orbits for electron path?
The uncertainty in momentum of an electron is $1\times 10^{-5} kg m/s.$ The uncertainty in its position will be (Given, $h = 6.62 \times 10^{-34} kg m^2/s)$
Gammexane is
A $ 500 \,kg $ car takes a round turn of radius $ 50\, m $ with a velocity of $ 36\, km/h $ . The centripetal force is
The current in the given circuit is
The internal resistance of a cell of e.m.f. 2 V is $0.1\, \Omega$ It is connected to a resistance of $3.9\, \Omega$. The voltage across the cell will be
In a meter bridge, the balancing length from the left end (standard resistance of one ohm is in the right gap) is found to be 20 cm. The value of the unknown resistance is
A potentiometer consists of a wire of length 4 m and resistance $10\, \Omega$ It is connected to a cell of e.m.f. 2 V. The potential difference per unit length of the wire will be
The resistance of a discharge tube is
The escape velocity of a sphere of mass m is given by (G = Universal gravitational constant; M = Mass of the earth and R = Radius of the e earth)
What is the effective capacitance between points X and y?
When air is replaced by a dielectric medium of constant K, the maximum force of attraction between two charges separated by a distance
The canal system is a characteristic feature of
Life span of a worker bee is
The new varieties of plants are produced by
Angiosperm, to which the largest flowers belong, is
Haemophilic man marries a normal woman. Their offsprings will be
A disc is rolling (without slipping) on a horizontal surface. C is its centre and Q and P are two points equidistant from C. Let $v_P$, $v_q$ and $v_c$ be the magnitude of velocities of points P,Q and C respectively, then
A gene pair hides the effect of another gene. The phenomenon is called

Energy transfer from one trophic level to another, in a food chain, is

Which of the following is true about bryophytes ?