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

A wheel of moment of inertia 1 kg.m² is rotating at a speed of 30 rad/s. Due to friction on the axis, it comes to rest in 10 minutes. Calculate the average torque of the friction.

State the Stefan-Boltzmann law.

A pair of adjacent coils has a mutual inductance of 1.5 H. If the current in one coil changes from 0 to 10 A in 0.2 s, what is the change of flux linkage with the other coil?

An emf of 96.0 mV is induced in the windings of a coil when the current in a nearby coil is increasing at the rate of 1.20 A/s. What is the mutual inductance (M) of the two coils?

A long solenoid of length l, cross-sectional area A and having N₁ turns (primary coil), has a small coil of N₂ turns (secondary coil) wound about its center. Determine the Mutual inductance (M) of the two coils.

Calculate the energy radiated in one minute by a blackbody of surface area 100 cm² when it is maintained at 227°C. (Given: σ = 5.67 × 10⁻⁸ W/m².K⁴)

A small blackened solid copper sphere of radius 2.5 cm is placed in an evacuated chamber. The temperature of the chamber is maintained at 100 °C. At what rate must energy be supplied to the copper sphere to maintain its temperature at 110 °C? (Take Stefan’s constant σ to be 5.67 × 10^-8 J s^-1 m^-2 K^-4) and treat the sphere as a blackbody.)

A wire loop of the form shown in the following figure carries a current I. Obtain the magnitude and direction of the magnetic field at P. (Given: `B = (mu_0I)/(4pir) sqrt2` due to

The magnetic field at the centre of a circular current carrying loop of radius 12.3 cm is 6.4 × 10^-6 T. What is the magnetic moment of the loop?

A circular loop of radius 9.7 cm carries a current 2.3 A. Obtain the magnitude of the magnetic field
(a) at the centre of the loop
(b) at a distance of 9.7 cm from the centre of the loop but on the axis.

The mutual inductance of two coils is 10 mH. If the current in one of the coil changes from 5 A to 1 A in 0.2 s, calculate the emf induced in the other coil. Also calculate the induced charge flowing through the coil if its resistance is 5 Ω.

Answer in one sentence.

State the SI unit and dimensions of stress.

In the law of tension, the fundamental frequency of the vibrating string is, ______   

State law of tension.

State law of linear density.

What is the resonance?

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

A sonometer wire of length 1 m is stretched by a weight of 10 kg. The fundamental frequency of vibration is 100 Hz. Determine the linear density of the material of the wire.

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.

State and verify the laws of vibrating strings using a sonometer.