Atoms — Physics STD 12 Science — Question

If the magnetic flux is expressed in weber, then magnetic induction can be expressed in

The majority charge carriers in P-type semiconductor are (a) Electrons(b) Protons(c) Holes(d)  Neutrons

The materials suitable for making electromagnets should have:

In which of the following situations, the heavier of the two particles has smaller de Broglie wavelength? The two particles:

In a streamline flow:

1. The speed of a particle always remains same.
2. The velocity of a particle always remains same.
3. The kinetic energies of all the particles arriving at a given point are the same.
4. The momenta of all the particles arriving at a given point are the same.

Correct exposure for a photographic print is 10 seconds at a distance of one metre from a point source of 20 candela. For an equal fogging of the print placed at a distance of 2 m from a 16 candela source, the necessary time for exposure is(a) 100 sec(b) 25 sec(c) 50 sec   (d) 75 sec

In an amplitude modulated wave for audio frequency of 500 cycle/second, the appropriate carrier frequency will be(a) 50 cycles/sec(b) 100 cycles/sec(c) 500 cycles/sec(d) 50,000 cycles/sec

Tangent galvanometer is used to measure(a) Steady currents(b) Current impulses(c) Magnetic moments of bar magnets(d) Earth's magnetic field

In a radioactive decay, neither the atomic number nor the mass number changes. Which of the following particles is emitted in the decay?