List of top Physics Questions

A parallel plate capacitor has a uniform electric field ‘ E → ’ in the space between the plates. If the distance between the plates is ‘d’ and the area of each plate is ‘A’, the energy stored in the capacitor is : (ε₀=permittivity of free space)

A convex lens ‘A’ of focal length 20 cm and a concave lens ‘B’ of focal length 5 cm are kept along the same axis with a distance ‘d’ between them. If a parallel beam of light falling on ‘A’ leaves ‘B’ as a parallel beam, then the distance ‘d’ in cm will be

In the product \(\vec{F}=q(\vec{v}\times\vec{b})\) 
=\(q\vec{v}\times(B\hat i+B \hat j+B_0\hat k)\)
 For q=1 and \(\vec v = 2\hat i+4\hat j+6\hat k\) and \(\vec F=4\hat i-20\hat j+12\hat k\)
What will be the complete expression for \(\vec B\)  ?

A point object is placed at a distance of 60 cm from a convex lens of focal length 30 cm. If a plane mirror were put perpendicular to the principal axis of the lens and at a distance of 40 cm from it, the final image would be formed at a distance of

A dipole is placed in an electric field as shown. In which direction will it move

A small block slides down on a smooth inclined plane, starting from rest at time t=0. Let Sn be the distance traveled by the block in the interval t=n−1 to t=n. Then, the ratio \(\frac{S_n}{S_{(n+1)}}\)

Match Column - I and Column - II and choose the correct match from the given choices. 

For a plane electromagnetic wave propagating in x-direction, which one of the following combination gives the correct possible directions for electric field (E) and magnetic field (B) respectively

Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional force are 10% of the input energy. How much power is generated by the turbine (g=10 m/s²)

A cup of coffee cools from 90°C to 80°C in t minutes, when the room temperature is 20°C. The time taken by a similar cup of coffee to cool from 80°C to 60°C at a room temperature same at 20°C is

A capacitor of capacitance ‘C’, is connected across an ac source of voltage V, given by V=V₀sinωt The displacement current between the plates of the capacitor, would then be given by

A uniform conducting wire of length 12a and resistance ‘R’ is wound up as a current-carrying coil in the shape of, 
(i) an equilateral triangle of side ‘a’. 
(ii) a square of side ‘a’. 
The magnetic dipole moments of the coil in each case respectively are:

A car starts from rest and accelerates at 5 m/s² . At t=4 s, a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at t=6 s? (Take g=10 m/s²)

The number of photons per second on average emitted by the source of monochromatic light of wavelength 600 nm, when it delivers the power of 3.3×10⁻³ watt will be : (h=6.6×10⁻³⁴ Js)

A particle is released from height S from the surface of the Earth. At a certain height, its kinetic energy is three times its potential energy. The height from the surface of the earth and the speed of the particle at that instant are respectively

A thick current-carrying cable of radius ‘R’ carries current ‘I’ uniformly distributed across its cross-section. The variation of magnetic field B(r) due to the cable with the distance ‘r’ from the axis of the cable is represented by 

An infinitely long straight conductor carries a current of 5 A as shown. An electron is moving with a speed of 10⁵ m/s parallel to the conductor. The perpendicular distance between the electron and the conductor is 20 cm at an instant. Calculate the magnitude of the force experienced by the electron at that instant

The half-life of a radioactive nuclide is 100 hours. The fraction of original activity that will remain after 150 hours would be

A radioactive nucleus \(_{Z}^{A}\textrm{X}\) undergoes spontaneous decay in the sequence \(_{Z}^{A}\textrm{X}\)\(\rightarrow\)_Z-1B\(\rightarrow\)_Z-3C\(\rightarrow\)_Z-2D, where Z is the atomic number of element X. The possible decay particles in the sequence are

In a potentiometer circuit, a cell of EMF 1.5 V gives a balance point at 36 cm length of wire. If another cell of EMF 2.5V replaces the first cell, then at what length of the wire, the balance point occurs

Column - I gives certain physical terms associated with the flow of current through a metallic conductor. Column - II gives some mathematical relations involving electrical quantities. Match Column - I and Column - II with appropriate relations 

Two conducting circular loops of radii R₁ and R₂ are placed in the same plane with their centers coinciding. If R₁ > > R₂, the mutual inductance M between them will be directly proportional to

An inductor of inductance L, a capacitor of capacitance C and a resistor of resistance ‘R’ are connected in series to an ac source of potential difference ‘V’ volts as shown in the figure. The potential difference across L, C and R is 40 V, 10 V and 40 V, respectively. The amplitude of current flowing through LCR series circuit is 10√2 A. The impedance of the course is

An electromagnetic wave of wavelength ‘λ’ is incident on a photosensitive surface of negligible work function. If ‘m’ mass is of photoelectron emitted from the surface that has de-Broglie wavelength λ_d, then

From a circular ring of mass ‘M’ and radius ‘R’ an arc corresponding to a 90\(^{\circ}\) sector is removed. The moment of inertia of the remaining part of the ring about an axis passing through the centre of the ring and perpendicular to the plane of the ring is ‘K’ times ‘MR² ’. Then the value of ‘K’ is