Moving Charges and Magnetism — Physics STD 12 Science — Question

Which of the following cannot cause fission in a heavy nucleus

(a) a-particle

(b) Proton

(c) Deutron

(d) Laser rays

Radioactive element decays to form a stable nuclide, then the rate of decay of reactant   will vary with time (t) as shown in figure

(a)

(b)

(c)

(d)

If we express the energy of a photon in KeV and the wavelength in angstroms, then energy of a photon can be calculated from the relation

(a) E = 12.4 hv

(b) E = 12.4 h/

(c) E = 12.4/

(d) E = hv

Which of the following spectral series in hydrogen atom give spectral line of 4860 Å

(a) Lyman

(b) Balmer

(c) Paschen

(d) Brackett

The energy of hydrogen atom in its ground state is – 13.6 eV. The energy of the level corresponding  to the quantum number n is equal 5 is

(a) – 5.40 eV

(b) – 2.72 eV

(c) – 0.85 eV

(d) – 0.54 eV

In the given figure, when key k is closed, then direction of induced current in the coil B IS:

A conducting gas is in the form of a long cylinder. Current flows through the gas along the length of the cylinder. The current is distributed uniformly across the cross-section of the gas. Disregard thermal and electrostatic forces among the gas molecules. Due to the magnetic fields set up inside the gas and the forces which they exert on the moving ions, the gas will tend to:

The reason of colour in thin film is :

A circular loop carrying a current is replaced by ann equivalent magnetic dipole. A point on the axis of the loop is in:

Two parallel beams of electrons moving in the same direction produce a mutual force

(a) Of attraction in plane of paper

(b) Of repulsion in plane of paper

(c) Upwards perpendicular to plane of paper

(d) Downwards perpendicular to plane of paper