List of practice Questions

The coefficient of performance of a refrigerator is $5$. If the temperature inside freezer is $-20^{\circ }C, $ the temperature of the surroundings to which it rejects heat is
A photoelectric surface is illuminated successively by monochromatic light of wavelength $? $ and If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the surface of the material is (h = Planck's constant, c = speed of light)
The ratio of the specific heats $\frac{C_P}{C_V} = \gamma$ in terms of degrees of freedom (n) is given by :
The two ends of a metal rod are maintained at temperatures 100$^{\circ}$C and 110$^{\circ}$C. The rate of heat flow in the rod is found to be 4.0 J/s. If the end are maintained at temperatures 200$^{\circ}$C and 210$^{\circ}$C, the rate of heat flow will be
The cutting of DNA at specific locations became possible with the discovery of
The distinguishing test between methanoic acid and ethanoic acid is
Half-life period of a first order reaction is $10\, min$. Starting with initial concentration $12\, M$, the rate after $20\, min$ is
Molar enthalpy change for melting of ice is $6\, kJ / mol$. Then the internal energy change (in $k J / mol$ ) when $1$ mole of water is converted into ice at $1$ atm at $0^{\circ} C$ is Empty QImg
A population will not exist in Hardy-Weinberg equilibrium if
Which vector can clone a small fragment of DNA ?
On a frictionless surface, a block of mass $M$ moving at speed $v$ collides elastically with another block of same mass $M$ which is initially at rest. After collision the first block moves at an angle $\theta$ to its initial direction and has a speed $\frac{v}{3}$. The second block's speed after the collision is
Which of the following options represents the correct bond order ?
How does the electron gain enthalpies vary across a period and down a group?
A rocket is launched vertically upward from the surface of the earth with an initial velocity of $ 10 \,km/s $ . If the radius of the earth is $ 6400 \,km $ and atmospheric resistance is negligible. Find the distance above the surface of the earth that the rocket will go.
A solid sphere is rolling down an inclined plane. Then, the ratio of its translational kinetic energy to its rotational kinetic energy is
The species which cannot serve as an initiator for the free radical polymerisation, is
Among $P, S, Cl, F$, the elements with most negative and least negative electron gain enthalpy respectively, are
If getting a number greater than $4$ is a success in a throw of a fair die, then the probability of at least $2$ successes in six throws of a fair die is
If the solubility of a sparingly soluble salt $AX _{2}$ is $s\, mol / L$, the solubility product is
The number of $Na$ atom in $46\, g \,Na$ (atomic weight of $Na= 23$) is
Consider boiling water converting into steam. Under this condition, the specific heat of water is
In a cyclic process, the change in the internal energy of a system over one complete cycle
In an $n-p-n$ transistor, $p$ is
Nylon is a
Among second period elements/the correct order for first ionisation enthalpy is