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

State unit and dimensions of Magnetic susceptibility.

The co-efficient of mutual induction between primary and secondary coil is 2H. Calculate induced e.m.f. if current of 4A is cut off in 2.5 x 10^-4 seconds

Electric intensity due to a charged sphere at a point outside the sphere decreases with...................

A conductor of any shape, having area 40 cm² placed in air is uniformly charged with a charge 0* 2µC. Determine the electric intensity at a point just outside its surface. Also, find the mechanical force per unit area of the charged conductor.

[∈₀=8.85x10^-12 S.I. units]

Electric field intensity in free space at a distance ‘r’ outside the charged conducting sphere of radius ‘R’ in terms of surface charge density ‘ a ’ is............................

(a)`sigma / in_0[R/r]^2`

(b)`in_0/sigma[R/r]^2`

(c)`R/r[sigma/in_0]^2`

(d)`R/sigma[r/in_0]^2`

The magnetic flux through a loop varies according to the relation Φ = 8t² + 6t + C, where ‘C’ is constant, 'Φ' is in milliweber and 't' is in second. What is the magnitude of induced e.m.f. in the loop at t = 2 seconds.

If the radius of a sphere is doubled without changing the charge on it, then electric flux originating from the sphere is ______.

A solenoid of length 1.5 m and 4 cm in diameter possesses 10 turns per metre. A current of 5 A is flowing through it. The magnetic induction at a point inside the solenoid along the axis is ............................. .

(μ₀ = 4π × 10^-7 Wb/Am)

1. π  × 10^-5 T
2. 2π × 10^-5 T
3. 3π × 10^-5 T
4. 4π × 10^-5 T

Explain the phenomenon of self induction

Draw a neat labelled diagram of a parallel plate capacitor completely filled with dielectric.

Electrostatic energy of 3·5 x 10^-4 J is stored in a capacitor at 700 V. What is the charge on the capacitor?

A metal rod `1/sqrtpi `m long rotates about one of its ends perpendicular to a plane whose magnetic induction is 4 x 10^-3 T. Calculate the number of revolutions made by the rod per second if the e.m.f. induced between the ends of the rod is 16 mV.

A network of four capacitors of 6 μF each is connected to a 240 V supply. Determine the charge on each capacitor.

Intensity of electric field at a point close to and outside a charged conducting cylinder is proportional to ______. (r is the distance of a point from the axis of cylinder)

(A) `1/r`

(B) `1/r^2`

(C) `1/r^3`

(D) r³

The magnetic flux through a loop is varying according to a relation `phi = 6t^2 + 7t + 1` where `phi` is in milliweber and t is in second. What is the e.m.f. induced in the loop at t = 2 second?

Explain self induction and mutual induction

A cube of marble having each side 1 cm is kept in an electric field of intensity 300 V/m. Determine the energy contained in the cube of dielectric constant 8. [Given : ∈₀ = 8.85  10^–12 C^2/Nm^2]

Obtain an expression for electric field intensity at a point outside uniformly charged thin plane sheet.

Derive an expression for e.m.f. and current in terms of turns ratio

Prove theoretically  (electromagnetic induction) `e = (dphi)/(dt)`