List of top Physics Questions

Assertion (A): Object at radius of curvature of biconvex lens made by glass (u = 1.5) form image at same distance an other side of the lens.
Reason (R): Image of a real object formed by concave lens is always virtual and erect.

A body is projected vertically upwards with a velocity u. It crosses a point in its journey at a height h twice, just after 1 and 7 s. The value of $ \mu $ is ms-1 is: $ (g=10{{m}^{-2}}) $

A short bar magnet placed in a horizontal plane has its axis aligned along the magnetic north-south direction. Null points are found on the axis of the magnet at 14 cm from the centre of the magnet. The earth’s magnetic field at the place is 0.36 G and the angle of dip is zero. What is the total magnetic field on the normal bisector of the magnet at the same distance as the null−point (i.e., 14 cm) from the centre of the magnet? (At null points, field due to a magnet is equal and opposite to the horizontal component of earth’s magnetic field.)

Two waves are given by $y_1 = \cos \, (4t - 2x)$ and $y_2 = sin \, \big(4t - 2x + \frac{\pi}{4} \big).$ The phase difference between the two waves is

A plane square sheet of charge of side $0.5\, m$ has uniform surface charge density. An electron at $1\, cm$ from the centre of the sheet experiences a force of $1.6 \times 10^{-12}\, N$ directed away from the sheet. The total charge on the plane square sheet is $\left(\varepsilon_{0}=8.854 \times 10^{-12} C ^{2} m ^{-2}\, N ^{-1}\right)$

Show that the wavelength of electromagnetic radiation is equal to the de Broglie wavelength of its quantum (photon).

A convergent beam is incident on a convex lens. What will be the nature of the image formed ?

If the velocity of a charged particle has the component both in and perpendicular to the direction of the magnetic field then the path traced by the charged particle will be?

A circular disc is rotating about its own axis at uniform angular velocity \(\omega.\) The disc is subjected to uniform angular retardation by which its angular velocity is decreased to \(\frac {\omega}{2}\) during 120 rotations. The number of rotations further made by it before coming to rest is

The least count of a stop watch is $0.2\, s$. The time of $20$ oscillations of a pendulum is measured to be $25\, s$. The percentage error in the time period is

Two pendulums of lengths 100 cm and 121 cm start vibrating. At some instant the two are at the mean position in the same phase. After how many vibrations of the longer pendulum will the two be in the sam phase at the mean position again?

Match List I with List II:

List I	List II
(A) AM Broadcast	(I) 88 – 108 MHz
(B) FM Broadcast	(II) 540 – 1600 KHz
(C) Television	(III) 3.7 – 4.2 GHz
(D) Satellite Communication	(IV) 54 – 890 MHz

Choose the correct answer from the options given below:

The effect of rotation of the Earth on the value of acceleration due to gravity is

In a grid iron pendulum , there are 3 iron rods and 4 brass rods , Length of each brass rod is 50 cm . $\alpha $ of iron is $12 \times 10^{-6} \,/^{\circ} C$ and $\alpha $ of brass is $18 \times 10^{-6}\,/^{\circ} C$ . Length of each iron rod is

The unit of self-inductance is

$100\,g$ of ice is mixed with $100\,g$ of water at $100^\circ\,C$. What will be the final temperature of the mixture

A boy of mass 50 kg is standing at one end of a, boat of length 9 m and mass 400 kg. He runs to the other, end. The distance through which the centre of mass of the boat boy system moves is

A vessel, whose bottom has round holes with diameter $0.1\, m\, m$, is filled with water. The maximum height up to which water can be filled without leakage is (Surface tension of water $= 75$ dyne $cm^{-1}$ and $g = 1000\, cm\,s^{-2}$)

The centre of mass of a system of three particles of masses $1g, 2g$ and $3g$ is taken as the origin of a coordinate system. The position vector of a fourth particle of mass $4 g$ such that the centre of mass of the four particle system lies at the point $(1, 2, 3)$ is a $(\hat i + 2 \hat j + 3 \hat k)$ , where a is a constant. The value of $\alpha$ is

A capillary tube of radius r is dipped inside a large vessel of water. The mass of water raised above water level is M. If the radius of capillary is doubled, the mass of water inside capillary will be

The electrical resistance of a conductor depends upon

A series LCR circuit with R = 20 W, L = 1.5 H and C = 35 μF is connected to a variable-frequency 200 V ac supply. When the frequency of the supply equals the natural frequency of the circuit, what is the average power transferred to the circuit in one complete cycle?

The numerical ratio of displacement to the distance covered is always: