List of top Physics Questions

The earth is assumed to be a sphere of radius R. A platform is arranged at a height R from the surface of the earth. The escape velocity of a body from this platform is fve, where ve is its escape velocity from the surface of the earth. The value of f is :

Above Curie temperature :

A convex lens and a concave lens, each having same focal length of 25 cm, are put in contact to form a combination of lenses. The power in diopters of the combination is :

A square surface of side L m is in the plane of the paper. A uniform electric field \(\rightarrow\) E \(\bigg(\frac{V}{m}\bigg)\), also in the plane of the paper, is limited only to the lower half of the square surface, (see figure). The electric flux in SI units associated with the surface is :

A uniform rod of length l and mass m is free to rotate in a vertical plane about A. The rod initially in horizontal position is released. The initial angular acceleration of the rod is : (Moment of inertia of rod about A is \(\bigg(\frac{ml^2}{3}\bigg)\)

The momentum of a photon of energy 1 MeV in kg m/s, will be :

The velocity v of a particle at time t is given by v = at + \(\bigg(\frac{b}{t}+c\bigg)\), where a, b and c are constants, The dimensions of a, b and c are respectively : constants, The dimensions of a, b and c are respectively :

A charged particle enters a uniform magnetic field with a certain speed at right angles to it. In the magnetic field a change could occur in its

For angles of projection of a projectile at angles (45°θ) and (45° +-θ), the horizontal ranges described by the projectile are in the ratio of :

A capacitor is connected to a cell of emf E having some internal resistance r. The potential difference across the

Which of the following statements is true?

There are $26$ tuning forks arranged in the decreasing order of their frequencies. Each tuning fork gives $3$ beats with the next. The first one is octave of the last. What is the frequency of 18th tuning fork?

In Young's experiment when sodium light of wavelength 5893 $\mathring {A}$ is used, then 62 fringes are seen in the field of view. Instead, if violet light of wavelength 4358 $\mathring {A}$ is used, then the number of fringes that will be seen in the field of view will be

Light waves travel in vacuum along the y-axis. Which of the following may represent the wave front?

A cyclist starts from the centre $O$ of a circular park of radius one kilometre, reaches the edge $P$ of the park, then cycles along the circumference and returns to the centre along $QO$ as shown in figure. If the round trip takes ten minutes, the net displacement and average speed of the cyclist (in metre and kilometre per hour) is.........

Two coils of self inductance 2 mH and 8 mH are placed so close together that the effective flux in one coil is completely linked with the other. The mutual inductance between these coils is

In the given circuit, what will be the equivalent resistance between the points $A$ and $B$ ?

Which of the following quantities measured from different inertial reference frames are same?

A p-n-p transistor is said to be in active region of operation, when:

A teacher asked a student to connect N cells each of emf e in series to get a total emf of Ne. While connecting, the student, by mistake, reversed by polarity of n cells. The total emf of the resulting series combination is:

A Carnot engine whose sink is at 300 K has an efficiency of 40%. By how much should the temperature of source be increased so as to increase its efficiency by 50% of original efficiency?

Two short bar magnets P and Q are arranged such that their centres are on the X-axis and are separated by a large distance. The magnetic axes of P and Q are along X and Y axes respectively. At a point R, midway between their centres, if B is the magnitude of induction due to Q, the magnitude of total induction at R due to the both magnets is:

How many times more, the mass of the original star is to be larger than that of the sun for the formation of Black Hole?

The electrical potential on the surface of a sphere of radius r due to a charge $ 3\times {{10}^{-6}}C $ is 500 V. The intensity of electric field on the surface of the sphere is $ \left[ \frac{1}{4\pi {{\varepsilon }_{0}}}=9\times {{10}^{9}}N{{m}^{2}}{{C}^{-2}} \right] $ $ (in\text{ }N{{C}^{-1}}) $ :

A person walked up a stalled escalator in $90\, s$ . When standing on the same escalator, now moving, he is carried up in $60\, s$. How much time would it take him to walk up the moving escalator?