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

A short bar magnet is placed in an external magnetic field of 700 gauss. When its axis makes an angle of 30° with the external magnetic field, it experiences a torque of 0.014 Nm. Find the magnetic moment of the magnet, and the work done in moving it from its most stable to the most unstable position.

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A conductor rod of length (l) is moving with velocity (v) in a direction normal to a uniform magnetic field (B). What will be the magnitude of induced emf produced between the ends of the moving conductor?

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A conductor rod of length (l) is moving with velocity (v) in a direction normal to a uniform magnetic field (B). What will be the magnitude of induced emf produced between the ends of the moving conductor?

A gas in a closed container is heated with 10 J of energy, causing the lid of the container to rise 2m with 3N of force. What is the total change in energy of the system?

Give an example of some familiar process in which no heat is added to or removed from a system, but the temperature of the system changes.

A gas contained in a cylinder fitted with a frictionless piston expands against a constant external pressure of 1 atm from a volume of 5 liters to a volume of 10 liters. In doing so it absorbs 400J of thermal energy from its surroundings. Determine the change in the internal energy of the system.

A hypothetical thermodynamic cycle is shown in the figure. Calculate the work done in 25 cycles.

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A particle performs linear S.H.M. starting from the mean position. Its amplitude is A and time period is T. At the instance when its speed is half the maximum speed, its displacement x is ______.

Obtain the expression for the period of a magnet vibrating in a uniform magnetic field and performing S.H.M.

A particle performing linear S.H.M. of period 2π seconds about the mean position O is observed to have a speed of `"b" sqrt3` m/s, when at a distance b (metre) from O. If the particle is moving away from O at that instant, find the time required by the particle, to travel a further distance b.

The displacement of an oscillating particle is given by x = a sin ω t + b cos ω t where a, b and ω are constants. Prove that the particle performs a linear S.H.M. with amplitude A = `sqrt("a"^2 + "b"^2)`.

A wooden block of mass m is kept on a piston that can perform vertical vibrations of adjustable frequency and amplitude. During vibrations, we don’t want the block to leave the contact with the piston. How much maximum frequency is possible if the amplitude of vibrations is restricted to 25 cm? In this case, how much is the energy per unit mass of the block? (g ≈ π² ≈ 10 m/s^-2)

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When an air column in a pipe closed at one end vibrates such that three nodes are formed in it, the frequency of its vibrations is  _____ times the fundamental frequency.

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If two open organ pipes of length 50 cm and 51 cm sounded together produce 7 beats per second, the speed of sound is ______.

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The tension in a piano wire is increased by 25%. Its frequency becomes ______ times the original frequency.

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A string is fixed at the two ends and is vibrating in its fundamental mode. It is known that the two ends will be at rest. Apart from these, is there any position on the string which can be touched so as not to disturb the motion of the string? What will be the answer to this question if the string is vibrating in its first and second overtones? 

A photocell is used to automatically switch on the street lights in the evening when the sunlight is low in intensity. Thus it has to work with visible light. The material of the cathode of the photocell is ______.

If N_Red and N_Blue are the numbers of photons emitted by the respective sources of equal power and equal dimensions in unit time, then ______.

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The equation E = pc is valid ______.

A sonometer wire of length 0.5 m is stretched by a weight of 5 kg. The fundamental frequency of vibration is 100 Hz. Calculate the linear density of wire.