List of top Physics Questions

A current carrying closed loop in the form of a right angle isosceles triangle $ABC$ is placed in a uniform magnetic field acting along $AB$. If the magnetic force on the arm $BC$ is $\vec{F}$, the force on the arm $AC$ is
What fraction of the surface area of earth can be covered to establish communication by one geostationary statellite?
If two bodies stick together after collision and move as a single body, the collision is said to be
Sun is visible a little before the actual sunrise and until a little after the actual sunset. This is due to
If the equivalent capacitance between $P$ and $Q$ of the combination of the capacitors shown in figure below is $ 30\,\mu \,F $ , the capacitor $C$ is
The particle that cannot be accelerated by a cyclotron is
Position-time graph for motion with zero acceleration is
A car moving with a speed of $50 \,km\, h^{-1}$ can be stopped by applying brakes after moving atleast $6 \,m$. If the same car is moving at a speed of $100 \,km\, h^{-1}$ the minimum stopping distance is
The maximum power dissipated in an external resistance R, when connected to a cell of emf E and internal resistance r, will be
A gardener pushes a lawn roller through a distance $ 20\,m $ . If he applies a force of $ 20\,kg\,wt $ in a direction inclined at $ 60^{\circ} $ to the ground, the work done by him is
The current gain of a common base transistor circuit is 0.96. On changing the emitter current by 10.0 mA, the change in the base current will be
Water is used as a coolant in automobile radiators owing to its high
Magnetic flux of $10 \mu Wb $ is linked with a coil, when a current of 2 mA flows through it. What is the self inductance of the coil?
How many $ 1\,\mu F $ capacitors must be connected in parallel to store a charge of $1\, C$ with a potential of $110\, V$ across the capacitors?
A solid sphere rolls down two different inclined planes of same height, but of different inclinations. ln both cases
A circular disc of radius $R$ is removed from a bigger circular disc of radius $2 R$ such that the circumferences of the discs touch. The centre of mass of the new disc is at a distance $\alpha R$ from the centre of the bigger disc. The value of $\alpha$ is
A man stands in a narrow, steep-sided valley. When he shouts he hears two echoes, one after l s and other after 2 s. If the velocity of sound in air is 330 m/s, the width of the valley is
Fusion reaction takes place at high temperature because
An electron in the hydrogen atom jumps from excited state n to the ground state. The wavelength so emitted illuminates a photosensitive material having work function $2.75 \,eV$. If the stopping potential of the photoelectron is $10 \,V$ , then the value of $n$ is
A body is moving with velocity $30\, ms$ towards east After 10 s its velocity becomes $40 \,ms$ towards north. The average acceleration of the body is
A radioactive nucleus of mass $M$ emits a photon of frequency $\upsilon$ and the nucleus recoils. The recoil energy will be
An electric dipole is placed in an uniform electric field with the dipole axis making an angle $ \theta $ with the direction of the electric field. The orientation of the dipole for stable equilibrium is
A TV tower has a height 150 m. What is the total population covered by the TV tower, if the population density around the TV tower is $10^3\, km^{-2}?$ Radius of the earth is $6.4\times10^{6}m$
A constant torque of $ 3.14\,Nm $ is exerted on a pivoted wheel. If the angular acceleration of the wheel is $ 4\pi \,rad/s^{2}, $ then the moment of Inertia of the wheel is
A radioactive nucleus of mass number $A$, initially at rest, emits an $ \alpha$ - particle with a speed $v$. The recoil speed of the daughter nucleus will be