List of top Physics Questions

When three identical bulbs of 60 watt 200 volt rating are connected in series to a 200-volt supply, the power drawn by them will be

A block of mass $m$ is placed on a smooth wedge of inclination $\theta$. The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block will be ($g$ is acceleration due to gravity)

A galvanometer acting as a voltmeter will have

The half-life of radium is about 1600 years. Of 100g of radium existing now, 25g will remain undecayed after

In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in the USA. If the resistance of a 60W bulb for use in India is R, The resistance of a 60W bulb for use in the USA will be

Source of sound and the observer are mutually at rest. If the speed of sound is changed, then the frequency of sound heard by the observer will appear to be

The energy stored in a condenser is in the form of

Two springs of spring constants $ k_1 $ and $ k_2$ are joined in series. The effective spring constant of the combination is given by

A galvanometer of $50$ ohm resistance has $25$ divisions. $A$ current of $ 4\times 10^{-4}$ ampere gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of $25$ volts, it should be connected with a resistance of

A body of mass $m$ rests on horizontal surface, the coefficient of friction between the body and the surface is $\mu$. if the mass is pulled by a force $P$ as shown in the figure, the limiting friction between body and surface will be:

A bar magnet is equivalent to ............

Blowing air with open mouth is an example of ...........

Sound waves in air are always longitudinal because,

Oxygen is $16$ times heavier than hydrogen. Equal volumes of hydrogen and oxygen are mixed. The ratio of speed of sound in the mixture to that in hydrogen is _____

Effective capacitance between A and B in the figure shown is (all capacitances are in $\mu\, F$ )

A bullet moving with a speed of $100\, ms ^{-1}$ can just penetrate two planks of equal thickness. Then, the number of such planks penetrated by the same bullet when the speed is doubled will be ...........

Of the diodes shown in the following diagrams, which one of the diode is reverse biased ?

A thin plano-convex lens acts like a concave mirror of focal length $0.2\, m$ when silvered from its plane surface. The refractive index of the material of the lens is $1.5.$ The radius of curvature of the convex surface of the lens will be ............

An unknown resistance $R_{1}$ is connected in series with a resistance of $10 \Omega .$ This combination is connected to one gap of a metre bridge while a resistance $R_{2}$ is connected in the other gap. The balance point is at $50\, cm$. Now, when the $10 \Omega$ resistance is removed the balance point shifts to $40 cm$. The value of $R_{1}$ is (in ohm)

A spherical drop of capacitance $1 \mu \,F$ is broken into eight drops of equal radius. Then, the capacitance of each small drop is ........

Three long straight wires $A, B$ and $C$ are carrying currents as shown in figure. Then the resultant force on $B$ is directed .............

A proton enters a magnetic field parallel to the direction of the field. Then, the path followed by it is

MP denotes the mass of a proton and Mn that of a neutron. A given nucleus, of binding energy B, contains Z protons and N neutrons. The mass M(N, Z) of the nucleus is given by (c is the velocity of light )

A vector $ Q\to $ which has a magnitude of 8 is added to the vector $ P\to $ , which lies along the X-axis. The resultant of these two vectors is a third vector $ R\to $ , which lies along the Y-axis and has a magnitude twice that of $ P\to $ .The magnitude of $ P\to $ is :