HSC Science (Computer Science) 12th Standard Board Exam - Maharashtra State Board Important Questions

A dipole with its charges, - q and + q located at the points (O, -b, O) and (O, +b, O) is present in a uniform electric field E. The equipotential surfaces of this field are planes parallel to the yz plane.

(a) What is the direction of the electric field E?

(b) How much torque would the dipole experience in this field?

State law of length.

State law of linear density.

How the frequency of the vibrating wire is affected if the load is fully immersed in water? 

Show that even as well as odd harmonics are present as an overtone in modes of vibration of the string. 

Waves produced by two vibrators in a medium have wavelength 2 m and 2.1 m respectively. When sounded together they produce 8 beats/second. Calculate wave velocity and frequencies of the vibrators.

A dipole is placed in a uniform electric field, its potential energy will be minimum when the angle between its axis and field is ______ 

If an electron is brought towards another electron, the electric potential energy of the system ______.

Which physical quantity has its unit as J/C? Is it a scalar or vector?

Obtain an expression for the capacitance of a parallel plate capacitor without a dielectric. 

Three-point charges +q, +2q and Q are placed at the three vertices of an equilateral triangle. Find the value of charge Q (in terms of q), so that the electric potential energy of the system is zero. 

The angle at which maximum torque is exerted by the external uniform electric field on the electric dipole is ______.

State the formula giving the relation between electric field intensity and potential gradient.

An electric dipole consists of two opposite charges each of magnitude 1 μC, separated by 2 cm. The dipole is placed in an external electric field of 10⁵ N/C. Calculate the:

1. maximum torque experienced by the dipole and
2. work done by the external field to turn the dipole through 180°.

Derive an expression for energy stored in a capacitor.

The work done in bringing a unit positive charge from infinity to a given point against the direction of electric field is known as ______.

A spherical metal ball of radius 15 cm carries a charge of 2μC. Calculate the electric field at a distance of 20 cm from the center of the sphere.

Define emissive power and coefficient of emmision of a body.

For polyatomic molecules having 'f' vibrational modes, the ratio of two specific heats,Cp/Cv  is..........

A metal sphere cools at the rate of 4°C / min. when its temperature is 50°C. Find its rate of cooling at 45°C if the temperature of surroundings is 25°C.