Electromagnetic Waves — Physics STD 12 Science — Question

When a body is charged by induction, then the body.

The antiparticle of electron is:

An electric bulb illuminates a plane surface. The intensity of illumination on the surface at a point 2m away from the bulb is 5  phot (lumen/cm²). The line joining the bulb to the point makes an angle of 60^o with the normal to the surface. The intensity of the bulb in candela is

(a) 40

(b) 40

(c) 20

(d) 40

Two protons are kept at a separation of 10nm. Let F_n and F_e be the nuclear force and the electromagnetic force between them:

1. F_e = F_n.
   
2. F_e >> F_n.
   
3. F_e << F_n.
   
4. F_e and F_n differ only slightly.
   

The ratio of contributions made by the magnetic field and electric field components to the intensity of an EM wave is:

Magnetic field inside a solenoid is:

Consider the situation shown in figure. The straight wire is fixed but the loop can move under magnetic force. The loop will:

In an X-ray tube electrons bombarding the target produce X-rays of minimum wavelength 1 Å. What must be the energy of bombarding electrons

(a) 13375 eV

(b) 12375 eV

(c) 14375 eV

(d) 15375 eV

Assertion  : Isobars are the element having same mass number but different atomic number.

Reason      : Neutrons and protons are present inside nucleus.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If the assertion and reason both are false.