List of practice Questions

Leaf cuttings are used in propagation of

A clock with an iron pendulum keeps correct time at $15^{\circ} C$. If the room temperature rises to $20^{\circ} C$ , the error in seconds per day will be (coefficient of linear expansion for iron is $0.000012/^{\circ} C$ )

Blastos is

In $Pencillium$, the spores called conida, develop

A clock with a metal pendulum beating seconds keeps correct time at 0$^{\circ}$C. If it loses 12.5 s a day at 25$^{\circ}$C, the coefficient of linear expansion of metal pendulum is

A circular racetrack of radius $300 \,m$ is banked at an angle of $15^?.$ The coefficient of friction between the wheels of a race car and the road is $0.2$, the maximum permissible speed to avoid slipping is

A circular ring of diameter $20\,cm$ has a resistance of $0.01$ $\Omega$. The ring is turned from a position perpendicular to a uniform magnetic field of $2T$ to a position parallel to the field. The amount of charge flowing through the ring in this process is

A circular copper disc $10 \,cm$ in diameter rotates at $1800$ revolution per minute about an axis through its centre and at right angles to disc. A uniform field of induction $B$ of $1\, Wb\, m^{-2}$ is perpendicular to disc, What potential difference is developed between the axis of the disc and the rim?

$A$ circular coil of wire consisting of $100$ turns each of radius $9 \,cm$ carries a current of $0.4 \,A$. The magnitude of magnetic field at the centre of the coil is

A circular coil with a cross-sectional area of $4\, cm^{2}$ has $10$ turns. It is placed at the centre of a long solenoid that has $15$ turns/cm and a cross-sectional area of $10\, cm^{2}$, as shown in the figure. The axis of the coil coincides with the axis of the solenoid. What is their mutual inductance?

A circular coil of radius 25 cm, carries a current of 50 amperes. I f it has 35 turns, the flux density at the centre of the coil is (in $Wb/m^2$)

A circular coil of radius $6\, cm$ and $20$ turns rotates about its vertical diameter with an angular speed of $40\, rad \, s^{-1}$ in a uniform horizontal magnetic field of magnitude $2 \times 10^{-2}\, T$. If the coil form a closed loop of resistance $8 \,\omega$, then the average power loss due to joule heating is

A circular coil of radius $8\, cm$, $400$ turns and resistance $2 \,Omega$ is placed with its plane perpendicular to the horizontal component of the earths magnetic field. It is rotated about its vertical diameter through $180^{\circ}$ in $0.30\, s$. Horizontal component of earth magnetic field at the place is $3\times 10^{-5}\, T$ The magnitude of current induced in the coil is approximately

A circular coil of 100 turns and effective diameter 20cm carries a current of 0.5 A. It is to be turned in a magnetic field of B = 2.0 T from a position in which the normal to the plane of the coil makes an angle $\theta$ equals to zero to one in which $\theta$ equals to 180$^\circ$. The work required in this process is

A circular coil of 16 turns and radius 0.1 m carries a current of 0.75 A . Its plane is normal to the external magnetic field of strength 0.05T . When the coil is turned slightly, it oscillates with a frequency of 2 Hz. Calculate the moment of inertia of the coil about the axis of rotation

A circular coil of diameter 2 cm and 100 turns is placed at the centre of a long solenoid of radius 5 cm and 10 turns/cm. The mutual inductance of the two coils will be nearest to:

If a normal chord at a point "t" on the parabola $y^2 = 4ax$ subtends a right angle at the vertex, then t =

The equation $x=\frac{e^t\,+\,e^{-t}}{2};y=\frac{e^1\,-\,e^{-t}}{2};t\in$ R represents

A chemical $'A?$ is used for the preparation of washing soda to recover ammonia. When $CO_2$ is bubbled through an aqueous solution of $'A?$, the solution turns milky. It is used in white washing due to disinfectant nature. What is the chemical formula of $'A'$ ?

A child is standing at one end of a long trolley moving with a speed $v$ on a smooth horizontal floor. If the child starts running towards the other end of the trolley with a speed $u$, the centre of mass of the system (trolley + child) will move with a speed

A child is standing with his two arms outstretched at the centre of a turntable that is rotating about its central axis with an angular speed $\omega_0$ . Now, the child folds his hands back so that moment of inertia becomes $3$ times the initial value. The new angular speed is

A charged particle with charge $q$ enters a region of constant, uniform and mutually orthogonal fields $\vec{E}$ and $\vec{B}$ with a velocity $\vec{V}$ perpendicular to both $\vec{E}$ and $\vec{B}$, and comes out without any change in its magnitude or direction Then

A chelating agent has two or more than two donor atoms to bind to a single metal ion. Which of the following is not a chelating agent?

A charged particle of charge Q arid mass m moves with velocity v in a circular path due to transverse magnetic field, B, then its frequency is

A charged oil drop is suspended in uniform field of $3 \times 10^4\, V/m$ so that it neither falls nor rises. The charge on the drop will be (Take the mass of the charge $= 9.9 \times 10^{-15}\, kg$ and $g = 10\, m/s^2)$