List of top Physics Questions

A particle of mass \( m \) is projected with velocity \( v \) at an angle \( \theta \) with the horizontal. At its highest point, it explodes into two pieces of equal mass. One of the pieces continues to move on the original trajectory. The velocity of the second piece is:
In a radioactive material, the activity at time \( t_1 \) is \( A_1 \) and at a later time \( t_2 \), it is \( A_2 \). If the decay constant of the material is \( \lambda \), then:

In the diagram shown below, both the strings AB and CD are made of the same material and have the same cross-section. The pulleys are light and frictionless. If the speed of the wave in string AB is \( v_1 \) and in CD is \( v_2 \), then the ratio \( \frac{v_1}{v_2} \) is: 
 

A ball is thrown vertically upwards with a velocity of \(19.6 ms^{–1}\) from the top of a tower. The ball strikes the ground after \(6 s\). The height from the ground up to which the ball can rise will be \((k/5) m\). The value of k is ______ (use \(g = 9.8 m/s^2\))

In 1st case, Carnot engine operates between temperatures 300 K and 100 K. In 2nd case, as shown in the figure, a combination of two engines is used. The efficiency of this combination (in 2nd case) will be:

Fig.
A man weighing 70 kg is riding on a cart of mass 30 kg which moves along a level floor at a speed of 3 ms-1. If he runs on the cart so that his velocity relative to the cart is 4ms-1 in the direction opposite to the motion of the cart, the speed of centre of mass of the system is

In the circuit shown, assume the diode to be ideal. When \( V_i \) increases from \(-2V\) to \(6V\), the change in current is (in mA): 

The work done by a force on body of mass 5 kg to accelerate it in the direction of force from rest to 20 m/s2 in 10 second is

A satellite of mass ‘m’ is revolving around the earth of mass ‘M’ in an orbit of radius ‘r’. The angular momentum of the satellite about the centre of orbit will be

A uniform electric field E = (8m/e) V/m is created between two parallel plates of length 1 m as shown in figure, (where m = mass of electron and e = charge of electron). An electron enters the field symmetrically between the plates with a speed of 2 m/s. The angle of the deviation (θ) of the path of the electron as it comes out of the field will be_______.
uniform electric field E

Sodium light of wavelengths 650 nm and 655 nm is used to study diffraction at a single slit of aperture 0.5 mm. The distance between the slit and the screen is 2.0 m. The separation between the positions of the first maxima of diffraction pattern obtained in the two cases is _____ × 10–5 m.

A car is moving with a speed of 54 km / h. If after 3 s, the driver applies brakes and it stops, then how much distance is covered by the car before coming to rest?
Two cylindrical vessels of equal cross-sectional area 16 cm2 contain water upto heights 100 cm and 150 cm respectively. The vessels are interconnected so that the water levels in them become equal. The work done by the force of gravity during the process, is [Take, density of water = 103 kg/m3 and g = 10 ms–2]
A water drop of diameter 2 cm is broken into 64 equal droplets. The surface tension of water is 0.075 N/m. In this process the gain in surface energy will be
An object is placed at the principal focus of a concave lens of focal length 10 cm. The image will be formed at___ cm, between the optical center and the focus of the lens on the same side of the object.
What is the maximum number of hydrogen bonds that a water molecule can make in the liquid state?
Calculate the temperature (in K) at which the resistance of a metal becomes 20% more than its resistance at 300 K. The value of the temperature coefficient of resistance for this metal is \(2.0 \times  10^{-4}\)/K.
A man throws a ball vertically up in the air with an initial velocity v1 such that it reaches a height of 12 m with a speed of 12 m/s. If he throws the same ball vertically up with an initial velocity v such that it reaches a maximum height of 12 m. Calculate v1/v2 (up to 2 decimal places).
What is the acceleration due to gravity (m/s²) on the surface of a planet if its radius is 1/4th that of earth and its mass is 1/80th that of earth" Assume that the gravity on the surface of the earth is 10 m/s².
The potential difference to accelerate an electron was quadrupled. By what factor does the de Broglie wavelength of the electron beam change?
A 500 nm light is used for imaging in a confocal microscope. What will be the best resolution (in nm) of this microscope?
An object is thrown vertically upwards. At its maximum height, which of the following quantity becomes zero?
In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to each other. A charged particle is released from rest in this region. The path of the particle will be a
A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be

The electric potential \( V(x) \) in a region around the origin is given by \( V(x) = 4x^2 \, {volts}. \) .The electric charge enclosed in a cube of 1m side with its center at the origin is (in coulomb)