List of top Physics Questions

A magnet makes 10 oscillations per minute at a place where the angle of dip is $45^{\circ}$ and the total intensity is 0,4 gauss. The number of oscillations made per sec by the same magnet at another place where the angle of dip is $60^{\circ} $ and the total intensity 0.5 gauss is approximately.
A magnet of length 10 cm and magnetic moment $1Am^2$ is placed along the side of an. equilateral triangle of the side AB of length 10 cm. The magnetic induction at third vertex third vertex C is
A magnet is moved towards the coil (i) quickly (ii) slowly then the induced emf is
A long solenoid with radius 2 cm carries a current of 2A. The solenoid is 70 cm long and is composed of 300 turns of wire. Calculate flux linked with a circular surface if it has radius greater than 2 cm and axis of solenoid subtends an angle of $60^\circ$ with the normal to the area (the centre of circular surface being on the axis of solenoid)
A long circular tube of length $10\, m$ and radius $0.3 \,m $ carries a current $I$ along its curved surface as shown. A wire-loop of resistance $0.005$ ohm and of radius $0.1 \,m $ is placed inside the tube with its axis coinciding with the axis of the tube
The current varies as $I=I_{0}\, cos(300t)$ where $I_{0}$ is constant. If the magnetic moment of the loop is $N\mu_{0}I_{0}sin(300t)$, then $N$ is
A liquid is kept in a cylindrical jar, which is rotated about the cylindrical axis. The liquid rises at its sides. The radius of the jar is 'r' and speed of rotation is $'\omega'$. The difference in height at the center and the sides of the jar is
A liquid having co-efficient of cubical expansion $\gamma$ is filled in the container having co-efficient of linear expansion as $\alpha$. If, on heating, the liquid overflows, then which of the following relations is correct ?
A liquid flows through two capillary tubes fitted horizontally side by side to the bottom of a vessel containing liquid. Their lengths are I and 21 and radii are r and 2r respectively. If 'V' is the volume of the liquid that fows through the first tube in one minute, the time required for the same volume of liquid to flow through the second tube is
A light string passes over a frictionless pulley. To one of the ends of the string a mass of 6 kg is attached. To the other end a mass of 10 kg is attached. Tension in the string is
A lens of power +3.5 diopters is placed in contact with a lens of power -2.5 diopter. The combination will behave like:
A lamina is made by removing a small disc of diameter $2R$ from a bigger disc of uniform mass density and radius $2R$, as shown in the figure. The moment of inertia of this lamina about axes passing through $O$ and $P$ is $I_0$ and $I_P$ respectively. Both these axes are perpendicular to the plane of the lamina. The ratio $\frac{I_P}{I_0}$
A jet airplane travelling at the speed of $ 500 \,km \,h^{-1} $ ejects its products of combustion at the speed of $ 1500 \,km\, h^{-1} $ relative to the jet plane. The speed of the products of combustion with respect to an observer on the ground is
A juggler throws balls into air. He throws one when ever the previous one is at its highest point. If he throws $ n $ balls each second, the height to which each ball will rise is
A jet plane is travelling west at the speed of $1600\, km \,h^{-1}$. The voltage difference developed between the ends of the wing having a span of $20\, m$, if the earth?s magnetic field at the location has a magnitude of $5 \times 10^{-4}\, T$ and the dip angle is $30^{\circ}$ is
A hydrogen like atom (atomic number Z) is in a higher excited state of quantam number n. This excited atom can make a transition to the first excited state by emitting a photon of energy 27.2eV. Alternatively the atom from the same excited state can make a transition to second excited state by emitting a photon of energy 10.20 eV The value of n and z are given (ionization energy of hydrogen atom is 13.6eV)
A hollow sphere partly filled with water has moment of inertia I when it is rotating about its own axis at an angular velocity $\omega$. If its angular velocity is doubled then its moment of inertia becomes
A hollow glass prism gives
Time period of a simple pendulum of length $l$ is $T_{1}$, and time period of a uniform rod of the same length $l$ pivoted about one end and oscillating in a vertical plane is $T_{2}$. Amplitude of oscillation in both the cases is small. Then $T_{1}/T_{2}$ is
An insulator plate is passed between the plates of a capacitor. Then the displacement current
A hole is drilled in a copper sheer. The diameter of the hole is 4.24 cm at 27.0$^\circ$C . What is the change in the diameter of the hole when the sheet is heated to 227$^\circ$C ? Coeffecient of linear expansion of copper = $1.70 \times 10^{-5}\,K^{-1}$
A circuit consists of five identical conductors as shown in figure. The two similar conductors are added as indicated by the dotted lines. The ratio of resistances before and after addition will be
A hiker stands on the edge of a cliff $490\,m$ above the ground and throws a stone horizontally with a speed of $15\,ms^{-1}$. The time taken by the stone to reach the ground is
A heavy box having a mass of $300\, kg$ is pulled along the floor for $10\, m$. If the coefficient of sliding friction is $0.2$, kilocalories of heat produced is
A helium nucleus makes full rotation in a circle of radius 0.8 min 2 s. The value of'magnetic field B at the centre of the circle, will be $(\mu _0=$ permeability constant)
A heavy nucleus at rest breaks into two fragments which fly off with velocities in the ratio 3 : 1. The ratio of radii of the fragments is