HSC Science (Electronics) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions

An electron is accelerated through a potential of 120 V. Find its de Broglie wavelength.

Calculate De Broglie's wavelength of the bullet moving with speed 90m/sec and having a mass of 5 gm. 

Explain De Broglie’s Hypothesis.

Obtain an expression for the decay law of radioactivity. Hence show that the activity A(t) =λN_O e^-λt.  

A 100 Ω resistor is connected to a 220 V, 50 Hz ac supply.

1. What is the rms value of current in the circuit?
2. What is the net power consumed over a full cycle?

The equation of a simple harmonic progressive wave travelling on a string is y = 8 sin (0.02x - 4t) cm. The speed of the wave is ______.

Plane wavefront of Light of wavelength 6000 Å is incident on two slits on a screen perpendicular to the direction of light rays. If the total separation of 10 brights fringes on a screen 2m away is 2 cm, find the distance between the slits.

With the help of a neat diagram, explain the reflection of Light on a plane-reflecting surface.

Calculate the value of magnetic field at a distance of 3 cm from a very long, straight wire carrying a current of 6 A.

Explain de-Broglie wavelength.

Obtain an expression for de-Broglie wavelength of wave associated with material particles. The photoelectric work function for metal is 4.2 eV. Find the threshold wavelength.

An electron is accelerated through a potential difference of 100 volts. Calculate de-Broglie wavelength in nm.

Calculate the velocity of a particle performing S.H.M. after 1 second, if its displacement is given by x = `5sin((pit)/3)`m.

A wire 5 m long is supported horizontally at a height of 15 m along an east-west direction. When it is about to hit the ground, calculate the average e.m.f. induced in it. (g = 10 m/s²)

A metal ring has a moment of inertia 2 kg·m² about a transverse axis through its centre. It is melted and recast into a thin uniform disc of the same radius. What will be the disc's moment of inertia about its diameter?

The gauge pressure 1 mm below the water surface open to the atmosphere is [Density of water = 10³ kg/m³, atmospheric pressure = 101.3 kPa, g = 10 m/s²]

A uniform disc of mass 10 kg and radius 60 cm rotates about an axis perpendicular to its plane and passing through its centre at 1200 rpm. Calculate its rotation kinetic energy. [Take π² = 10]

Assuming the expression for the pressure P exerted by an ideal gas, prove that the kinetic energy per unit volume of the gas is `3/2` P.

For a particle performing circular motion, when is its angular acceleration directed opposite to its angular velocity?

What is a stationary wave?