List of top Physics Questions

The surface tension of a liquid at its boiling point

Consider a badminton racket with length scales as shown in the figure.

If the mass of the linear and circular portions of the badminton racket are same (M) and the mass of the threads are negligible, the moment of inertia of the racket about an axis perpendicular to the handle and in the plane of the ring at, $\frac{r}{2}$ distance from the end A of the handle will be _________ $Mr^2$.

The magnitude of vectors $\vec{OA}$, $\vec{OB}$ and $\vec{OC}$ in the given figure are equal. The direction of $\vec{OA} + \vec{OB} - \vec{OC}$ with x-axis will be :

A source and a detector move away from each other in absence of wind with a speed of 20 m/s with respect to the ground. If the detector detects a frequency of 1800 Hz of the sound coming from the source, then the original frequency of source considering speed of sound in air 340 m/s will be _________ Hz.

An amplitude modulated wave is represented by $C_m(t) = 10(1 + 0.2 \cos 12560 t) \sin(111 \times 10^4 t)$ volts. The modulating frequency in kHz will be _________.

Two short magnetic dipoles $m_1$ and $m_2$ each having magnetic moment of $1 \text{ Am}^2$ are placed at point O and P respectively. The distance between OP is 1 meter. The torque experienced by the magnetic dipole $m_2$ due to the presence of $m_1$ is _________ $\times 10^{-7} \text{ Nm}$.
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Two spherical balls having equal masses with radius of 5 cm each are thrown upwards along the same vertical direction at an interval of 3 s with the same initial velocity of 35 m/s, then these balls collide at a height of _________ m.
(take $g = 10 \text{ m/s}^2$)

A soap bubble of radius 3 cm is formed inside the another soap bubble of radius 6 cm. The radius of an equivalent soap bubble which has the same excess pressure as inside the smaller bubble with respect to the atmospheric pressure is _________ cm.

If E, L, M and G denote the quantities as energy, angular momentum, mass and constant of gravitation respectively, then the dimensions of P in the formula $P = E L^2 M^{-5} G^{-2}$ are :

The material filled between the plates of a parallel plate capacitor has resistivity 200 $\Omega$m. The value of capacitance of the capacitor is 2 pF. If a potential difference of 40 V is applied across the plates of the capacitor, then the value of leakage current flowing out of the capacitor is : (given the value of relative permittivity of material is 50)

The initial mass of a rocket is 1000 kg. Calculate at what rate the fuel should be burnt so that the rocket is given an acceleration of 20 $ms^{-2}$. The gases come out at a relative speed of 500 $ms^{-1}$ with respect to the rocket : [Use $g = 10 \text{ m/s}^2$]

In a photoelectric experiment ultraviolet light of wavelength 280 nm is used with lithium cathode having work function $\phi = 2.5$ eV. If the wavelength of incident light is switched to 400 nm, find out the change in the stopping potential. ($h=6.63 \times 10^{-34}$ Js, $c=3 \times 10^8$ $ms^{-1}$)

The rms speeds of the molecules of Hydrogen, Oxygen and Carbondioxide at the same temperature are $V_H$, $V_O$ and $V_C$ respectively then :

A particular hydrogen like ion emits radiation of frequency $2.92 \times 10^{15}$ Hz when it makes transition from n=3 to n=1. The frequency in Hz of radiation emitted in transition from n=2 to n=1 will be :

In a Screw Gauge, fifth division of the circular scale coincides with the reference line when the ratchet is closed. There are 50 divisions on the circular scale, and the main scale moves by 0.5 mm on a complete rotation. For a particular observation the reading on the main scale is 5 mm and the 20th division of the circular scale coincides with reference line. Calculate the true reading.

Two bodies of masses 8 kg are placed at the vertices A and B of an equilateral triangle ABC. A third body of mas 2 kg is placed at the centroid G of the triangle. If AG = BG = CG = 1 m, where should a fourth body of mass 4 kg be placed so that the resultant force on the 2 kg body is zero?

Which of the following waves are used in the treatment of muscle ache?

The displacement of a wave is given by $ y = 20 \cos(\omega t + 4x) $. The amplitude of the wave is

The function $ y = \log(\omega t) $ can represent

Radius of gyration of a solid cylinder of radius R and length L about its long axis of symmetry is

Two blocks of masses 3 kg and 5 kg are connected by a metal wire going over a smooth pulley. The breaking stress of the metal is $ \frac{24}{\pi} \times 10^2 $ Nm$^{-2}$. What is the minimum radius of the wire ?
(take g=10 ms$^{-2}$)

The solid cylinder of length 80 cm and mass M has a radius of 20 cm. Calculate the density of the material used if the moment of inertia of the cylinder about an axis CD parallel to AB as shown in figure is 2.7 kg m$^2$.

The angle between vector $ (\vec{A}) $ and $ (\vec{A} - \vec{B}) $ is:

Match List - I with List - II :

Choose the most appropriate answer from the options given below :

The acceleration due to gravity is found upto an accuracy of 4% on a planet. The energy supplied to a simple pendulum of known mass 'm' to undertake oscillations of time period T is being estimated. If time period is measured to an accuracy of 3%, the accuracy to which E is known as __________ %.