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

Explain the construction and working of sonometer hence explain its use to verify first law of vibrating string (Law of length).

In biprism experiment, the distance of 20^th bright band from the central bright band is 1.2 cm. Without changing the experimental set-up, the distance of 30^th bright band from the central bright band will be ______.

A and B are two steel wires and the radius of A is twice that of B. If they are stretched by the same load, then the stress on B is .....

The process of superimposing a low frequency signal on a high frequency wave is_______ .

State and prove: Law of conservation of angular momentum.

Obtain an expression for average power dissipated in a purely resistive A.C. circult. 

Define modulation and transducer

Draw a diagram showing all components of forces acting on a vehicle moving on a curved banked road. 

Wavelengths of two notes in the air are`[70/153]^m` and `[70/157]^m`. Each of  these notes produces 8 beats per second with a tuning fork of fixed frequency. Find the velocity of sound in the air and frequency of the tuning fork.

The ratio of diameters of two wires of the same material and length is n : 1. If the same load is applied to both the wires then increases in the length of the thin wire is ........................ (n > 1).

1. n^1/4 times
2. n^1/2 times
3. n times
4. n² times

Calculate the de Broglie wavelength of an electron moving with - of the speed of light in vacuum (Negelct relativistic effect)

(Planck's constant: h = 6.63 x 10^-34 Js, Mass of electron : m = 9.11 x 10^-28 g)

Write the functions of three segments of a transistor.

Reactance of a coil is 157 Ω. On connecting the coil across a source of frequency 100 Hz, the current lags behind e.m.f. by 45°. The inductance of the coil is ...........

(a) 0·25 H

(b) 0·5 H

(c) 4 H

(d) 314H

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

A mass of 1 kg is hung from a steel wire if radius 0.5 mm and length 4 m. Calculate the extension produced. What should be the area of cross-section of the wire so that elastic  limit is not exceeded? Change in radius is negligible

(Given : g = 9.8 m/s^2; Elastic limit of steel is 2.4 x 10⁸ N/m²;Y for steel (Ysteel) = 20 x 10¹⁰ N/m²; π = 3.142)

In Doppler effect of light, the term “red shift” is used for ______.

(A) frequency increase

(B) frequency decrease

(C) wavelength decrease

(D) frequency and wavelength increase

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]

Doppler effect is not applicable when _______.
(A) source and observer are at rest.
(B) there is a relative motion between source and observer.
(C) both are moving in opposite directions.
(D) both are moving in same direction with different velocities

Three capacitors of capacities 8 μF, 8 μF and 4 μF are connected in a series and potential difference of 120 volt is maintained across the combination. Calculate the charge  on capacitor of capacity 4 μF.