List of practice Questions

The magnetic field at the point of intersection of diagonals of a square loop of side $L$ carrying a current $I$ is

A $ 1\, kg $ block situated on a rough incline is connected to a spring of negligible mass having spring constant $ 100\, N\,m^{-1} $ as shown in the figure.

The block is released from rest with the spring in the unstretched position. The block moves $ 10\, cm $ down the incline before coming to rest. The coefficient of friction between the block and the incline is (Take $ g = 10\, ms^{-2} $ and assume that the pulley is frictionless)

A current $I$ flows along the length of an infinitely long, straight, thin-walled pipe. Then

$A= (1, -2, 3), B = (2, 1, 3), C = (4, 2, 1)$ and $G = (-1, 3, 5)$ is the centroid of the tetrahedron ABCD. If $p= D_y$ and $q = D_z$ then $ 13p-1.1q =$

A $0.5\, kg$ ball is thrown vertically up with $14 \,m s^{-1}$. It attains a height of $8\,m$. The energy dissipated by air drag acting on the ball during ascent is

A 1.0 mH inductance, a 10 $\mu F$ capacitance and a 5.0 ohm resistance are connected in series to an a.c. source. It is found that the inductor and the capacitor show equal reactances. The reactance should be nearest to

A $0.5\, dm^3$ flask contains gas $A$ and $1 \,dm^3$ flask contains gas $B$ at the same temperature. If density of $A = 3.0\, g\, dm^{-3}$ and that of $B = 1.5\, g\, dm^{-3}$ and the molar mass of $A=\frac{1}{2}$ of $B$, then the ratio of pressure exerted by gases is

A $0.2\, k\Omega$ resistor and $15\,\mu F$ capacitor are connected in series to a $220\,V$, $50\,Hz$ ac source. The impedance of the circuit is

$^{}_{92}U^{238}$ on absorbing a neutron goes over to $^{}_{92}U^{239} .$ This nucleus emits an electron to go over to neptunium which on further emitting an electron goes over to plutonium. The resulting plutonium can be expressed as.

96500 C electricity is passed through $CuSO_4$. The amount of copper precipitated is

Clouds appear to float in air due to

A small ball of density $\rho$ is immersed in a liquid of density $(\sigma > \rho)$ to a depth h and released. The height above the surface of water up to the ball will jump is

The S.I Unit of pressure is

8000 identical water drops combine together, to form a big drop. Then the ratio of the final surface energy to the initial surface energy of all the drops together is.

A body is dropped from a height of $4 \,m$ on a surface. If in collision $25\%$ of energy is lost, then the height upto which it will rise after collision is

If plane surface of a piano convex lens is silvered, then it will behave as a

The relationship between Young's modulus $Y$, bulk modulus $K$ and modulus of rigidity $\eta$ is

A closed iron ring is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet is

Longitudinal wave can travel in

The number of $\alpha$-particles and $\beta$-particles respectively emitted in the reaction $ {_{88}A^{196} -> _{78}B^{164}}$

$\left(^{8}C_{1} - ^{8}C_{2} + ^{8}C_{3} -^{8}C_{4} + ^{8}C_{5} - ^{8}C_{6} +^{8}C_{7} - ^{8}C_{8}\right) $ equals:

A projectile is projected with speed $49\,ms^{-1}$ at an angle of $30^{\circ}$ with horizontal. The time taken by the projectile to reach the highest point is

Real gas behaves as an ideal gas, under which of the following conditions ?

The electrical conductivity of a semiconductor increases when electromagnetic radiation of wave length shorter than $2480\, nm$ is incident on it. The band gap (in $eV$) for semiconductor is

The potential difference across the collector of a transistor, used in common emitter mode is $1.5\, V$, with the collector resistance of $3\, k\Omega$, the emitter current is $[\beta = 50]$