List of practice Questions

In the electric network shown, when no current flows through the $4\, \Omega$ resistor in the arm $EB$, the potential difference between the points $A$ and $D$ will be :

When $5\,V$ potential difference is applied across a wire of length $0.1\,m$, the drift speed of electrons is $2.5\times10^{-4}$ $ms^{-1}$. If the electron density in the wire is $8\times10^{28}\, m^{-3}$ the resistivity of the material is close to

The ionic radii (in $?$) of $N^{3-},O^{2-} $ and $F^-$ respectively are

The number of geometric isomers that can exist for square planar $\left[ Pt ( Cl )( py )\left( NH _{3}\right)\right.$ $\left.\left( NH _{2} OH \right)\right]^{+}$ is $( py =$ pyridine $):$

Which artificial sweetener contains chlorine ?

If $\log _{0.2}(x-1)>\log _{0.04}(x+5)$, then

The half life of a radioactive substance is $20\, minutes$. The time taken between $50\%$ decay and $87.5\%$ decay of the substance will be

A person is standing on a weighing-scale and observes that the reading is $60\,kg$ . He then suddenly jumps up and observes that reading goes to $70\,kg$ . Then his maximum upward acceleration is

Consider a spherical shell of radius $R$ at temperature $T$. The black body radiation inside it can be considered as an ideal gas of photons with internal energy per unit volume $u=\frac{U}{V} ? T^4$ and pressure $p=\frac{1}{3}\bigg(\frac{U}{V}\bigg)$ If the shell now undergoes an adiabatic expansion, the relation between $T$ and $R$ is

Consider an ideal gas confined in an isolated closed chamber. As the gas undergoes an adiabatic expansion, the average time of collision between molecules increases as $V^q$ , where $V$ is the volume of the gas. The value of $q$ is $\bigg(\gamma =\frac{C_p}{C_v}\bigg)$

A solid body of constant heat capacity $1 \, J/^{\circ}C$ is being heated by keeping it in contact with reservoirs in two ways (i) Sequentially keeping in contact with $2$ reservoirs such that each reservoir supplies same amount of heat. (ii) Sequentially keeping in contact with $8$ reservoirs such that each reservoir supplies same amount of heat. In both the cases, body is brought from initial temperature $100^{\circ}C$ to final temperature $200^{\circ}C$. Entropy change of the body in the two cases respectively, is

As an electron makes a transition from an excited state to the ground state of a hydrogen- like atom/ion

A long cylindrical shell carries positive surface charge $\sigma$ in the upper half and negative surface charge $-\sigma$ in the lower half. The electric field lines around the cylinder will look like figure given in: (figures are schematic and not drawn to scale)

A thin disc of radius $b\, = \,2a$ has a concentric hole of radius '$a$' in it (see figure). It carries uniform surface charge '$\sigma$' on it. If the electric field on its axis at height '$h$' $(h < < a)$ from its centre is given as '$Ch$' then value of '$C$' is :

Higher order $( > 3 )$ reactions are rare due to

Which of the following compounds is not colored yellow?

Which of the following statements is not correct?

Cell wall is absent in

Which one of the following is oviparous?

Filiform apparatus is characteristic feature of

Blood pressure in the mammalian aorta is maximum during

Glenoid cavity articulates

Write the set builder form $A = {-1, 1}$

If $\alpha$ and $\beta$ are the roots of $x^2 - ax + b^2 = 0$, then $\alpha^2 + \beta^2$ is equal to

A box contains $6$ red marbles numbers from $1$ through $6$ and $4$ white marbles $12$ through $15$. Find the probability that a marble drawn 'at random' is white and odd numbered.