List of top Physics Questions

For ordinary terrestial experiments, the observer in an inertial frame in the following cases is

___ system of units was accepted by the scientist of the general conference on weights and measures.

A car is standing $200\, m$ behind a bus, which is also at rest. The two start moving at the same instant but with different forward accelerations. The bus has acceleration $2 \, m/s^2$ and the car has acceleration $4 \, m/s^2$. The car will catch up with the bus after a time of :

The temperature of an open room of volume $30 \, m^3$ increases from $17^{\circ}C$ to $27^{\circ}C$ due to the sunshine. The atmospheric pressure in the room remains $1 \times 10^5 \, Pa$. If $n_i$ and $n_f$ are the number of molecules in the room before and after heating, then $n_f-n_i$ will be :

The moment of inertia of a uniform cylinder of length $l$ and radius $R$ about its perpendicular bisector is $l$. What is the ratio $\frac{l}{R}$ such that the moment of inertia is minimum ?

In a physical balance working on the principle of moments, when $5\,mg$ weight is placed on the left pan, the beam becomes horizontal. Both the empty pans of the balance are of equal mass. Which of the following statements is correct ?

A conical pendulum of length $1\,m$ makes an angle $\theta = 45^{\circ}$ w.r.t. $Z-axis$ and moves in a circle in the $XY$ plane. The radius of the circle is $0.4 \,m$ and its center is vertically below $O$. The speed of the pendulum, in its circular path, will be : (Take $g = 10 \, ms^{-2}$)

A uniform wire of length $l$ and radius $r$ has a resistance of $100 \, \Omega$ . It is recast into a wire of radius $\frac{r}{2}$. The resistance of new wire will be :

In the above circuit the current in each resistance is

Select the output Y of the combination of gates shown in figure for inputs A = 1, B = 0; A = 1, B = 1 and A = 0, B = 0 respectively.

An electron and a proton enter a magnetic field perpendicularly both have same kinetic energy. Which of the following is true?

The reason a moving coil galvanometer cannot be used with an alternating current is that

If the vertical component of earth's magnetic field at a place is √3 times the horizontal component, then the value of dip at that place is

The temperature co-efficient of resistance of a wire is 0.00125/°C. Its resistance is 1Ω at 300 K. At what temperature, its resistance will be 2Ω?

Two thin lenses have a combined power of +9D. When they are separated by a PY distance of 20 cm, their equivalent power becomes \(+\frac{27}{5}D\), then their individual powers are

In Young's double slit experiment, using a monochromatic light of wavelength λ, the intensity of light at a point on the screen where path difference is \(\lambda\) is K units. Then the intensity of light at a point where path difference is \(\frac{\lambda}{3}\) is

If the mass shown in figure is slightly displaced and then let go, then the system shall oscillate with a time period of

A 1 cm height needle is placed at a distance of 0.1 m from a convex mirror of focal length 0.05 m, then size of the image is

A transformer of efficiency 90% has turns ratio 1: 10. If the voltage across the primary is 220 V and current in the primary is 0.5 A, then the current in secondary is

Two long parallel wires placed 0.08 m apart carry currents 3 A and 5 A in the same direction. What is the distance from the conductor carrying larger current to the point where the resultant magnetic field is zero ?

The relative permeability is represented by μ_r and the susceptibility by X for a magnetic substance. Then for a paramagnetic substance

A copper wire of 3 mm² cross sectional area carries a current of 5 ampere. The magnitude of the drift velocity for the electrons in the wire, (Assume copper to be monovalent, M_cu 63.5 kg/k mol and density of copper = 8920 kg/m³)

Two identical charged spheres are suspended by strings of equal lengths. The strings make an angle of 30° with each other. When suspended in a liquid of density 0.8 g cm^-3 the angle remains the same. If density of the material of the sphere is 1.6 g cm^-3, the dielectric constant of the liquid is

In the circuit below, the potential difference between A and B is

A stream of water flowing horizontally with a speed of 15 ms^-1 gushes out of a tube of cross-sectional area 10^-2m² and hits a vertical wall nearly. The force exerted on the wall by the impact of water assuming it does not rebound is