List of top Physics Questions

Newton?? formula for the velocity of sound in gases, is
An aeroplane is flying horizontally with a velocity of 216 km/h and at a height of 1960 m. When it is vertically above a point A on the ground, a bomb is released from it. The bomb strikes the ground at point B. The distance AB is (ignoring air resistance)
The rate of difusion is
Which of the following pairs does not have same dimension?
A copper ball is heated to $ 100{}^\circ C $ . It cools to $ 80{}^\circ C $ in 5 minutes and to $ 65{}^\circ C $ in 10 minutes. The temperature of the surrounding is
A lift is ascending with an acceleration equal to g/3 What will be the time period of a simple pendulum suspended from its ceiling if its time period in stationary lift isT:
A galvanometer of 100 $ \Omega $ resistance gives full scale deflection with 0.01 A current. How much resistance should be connected to convert it into an ammeter of range , 10 A :
A spherical surface of radius of curvature R, separates air (refractive index 1.0) from glass (refractive index 1.5). The centre of curvature is in the glass. A point object P placed in air is found to have a real image Q in the glass. The line PQ cuts the surface at a point O and PO = O The distance PO is equal to
A ball of mass 0.25 kg attached to the ends of a string of length 1.96 m is rotating in a horizontal circle. The string will break, if tension is more than 25 N. What is the maximum velocity with which the ball can be rotated?
A coil of one turn is made of a wire of certain length and then from the same length a coil of two turns is made. If the same current is passed in both the cases, then the ratio of the magnetic inductions at their centres will be
A semiconducting device is connected in a series circuit with a battery and a resistance. A current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops to almost zero. The device may be
The position of both an electron and helium atom is known within $1.0 nm$. The momentum of the electron is known within $5.0 \times 10^{-26} kg ms ^{-1}$. The minimum uncertainty in the measurement of the momentum of the helium atom is
A point Q lies on the perpendicular bisector of an electrical dipole of dipole moment p. If the distance of Q from the dipole is r (much larger than the size of the dipole), then the electric field at Q is proportional to
The velocity of an electron in the innermost orbit of an atom is :
A heavy ball is thrown on a rough horizontal surface in such a way that it slides with a speed ($v_o$) initially without rolling. It will roll without sliding when its speed falls to:
When 2 equal resistances are connected in parallel to the poles of a cell of negligible internal resistance, the power developed is P. When the same resistances are connected in series across the same cell, the power developed is
A transverse wave is represented by the equation $y=y_0 \sin\frac{2\pi}{\lambda}(vt-x)$ For what value of $\lambda$, is the maximum particle velocity equal to two times the wave velocity?
Susceptibility of a magnetic substance is found to depend on temperature and the strength of the magnetising field. The material is a
The angular velocity of a body changes, from $ {{\omega }_{1}} $ to $ {{\omega }_{2}} $ without applying torque but by changing moment of inertia. The ratio of initial radius of gyration to the final radius of gyration is :
Device used to measure very high temperature is
A bullet is fired from a gun. The force on the bullet is given by $F=600-(2\times10^5)t$ where, F is in newton and t in seconds. The force on the bullet becomes zero as soon as it leaves the barrel. What is the average impulse imparted to the bullet?
A shell, in flight, explodes into four unequal parts. Which of the following is conserved?
Three equal resistors connected in series across a source of e.m.f. together dissipate 10 watt of power. What will be the power dissipated in watt if the same resistors are connected in parallel across the same source of e.m.f. ?
A ball is dropped from a height of 5 m on a planet where the acceleration due to gravity is not known. On bouncing it rises to 1.8 m. The ball loses its velocity on bouncing by a factor of
Two bodies of masses m and 4m are moving with equal kinetic energies. The ratio of their linear momenta is