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

Show that the number of nuclei of a radioactive material decreases exponentially with time.

Efficiency of transformer is the ratio of ______.

The half-life of \[\ce{^238_92U}\] undergoing ∝- -decay is 4.5 × 10⁹ years. What is the activity of 1g sample of \[\ce{^238_92U}\]?

Prove that the inductance of parallel wires of length l in the same circuit is given by L = `((mu_0l)/pi) "in" (d/a)` where 'a' is the radius of wire and d is seperation between wire axes.

Define half-life period.

In one mean lifetime of a radioactive element the fraction of the nuclei that has disintegrated is ______. [e is the base of natural logarithm]

The wires which connect the battery of an automobile to its starting motor carry a current of 300 A (for a short time). What is the force per unit length between the wires if they are 70 cm long and 1.5 cm apart? 

The self-inductance of a closely wound coil of 200 turns is 10 mH. Determine the value of magnetic flux through the cross-section of the coil when the current passing through the coil is 4 mA.

What is a transformer?

Derive the equation for a transformer.

The decay constant of radioactive substance is 4.33 x 10^-4 per year. Calculate its half life period.

A seconds pendulum is suspended in an elevator moving with constant speed in downward direction. The periodic time (T) of that pendulum is _______.

The periodic time of a linear harmonic oscillator is 2π second, with maximum displacement of 1 cm. If the particle starts from extreme position, find the displacement of the particle after π/3  seconds.

State the law of radioactive decay.

A copper metal cube has each side of length 1 m. The bottom edge of the cube is fixed and tangential force 4.2x10⁸ N is applied to a top surface. Calculate the lateral displacement of the top surface if modulus of rigidity of copper is 14x10¹⁰ N/m².

Derive the mathematical expression for law of radioactive decay for a sample of a radioactive nucleus

Represent Radioactive Decay curve using relation `N = N_o e^(-lambdat)` graphically

Answer in brief:

Derive an expression for the period of motion of a simple pendulum. On which factors does it depend?

The specific heat capacity of water is 

The length of the second’s pendulum in a clock is increased to 4 times its initial length. Calculate the number of oscillations completed by the new pendulum in one minute.