MCQ
In an atom, electrons revolve around the nucleus. This gives rise to:
  • A
    Only electric field.
  • B
    Only magnetic field.
  • C
    Both electric and magnetic fields.
  • D
    None of the above.

Answer

  1. Both electric and magnetic fields.

Explanation:

When a charge electron starts to move, electric current generates and this electric current generates magnetic field, a charge at rest also can generate electric field.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Unit of radioactivity is Rutherford. Its value is

(a) 3.7  disi tegrations/sec

(b) 3.7  disintegrations/sec

(c) 1.0  disintegrations/sec

(d) 1.0  disintegrations/sec

In the figure the charge Q is at the centre of the circle. Work done is maximum when another charge is taken from point P to

(a) K

(b) L

(c) M       

(d) N

What is the modulation index of an over modulated wave

(a) 1 

(b) Zero

(c) < 1

(d) > 1

Photoelectric effect shows:

To induce an e.m.f. in a coil, the linking magnetic flux

(a) Must decrease

(b) Can either increase or decrease

(c) Must remain constant

(d) Must increase

In the circuit shown, potential difference between X and Y will be

(a) Zero

(b) 20 V

(c) 60 V

(d) 120 V

A regular hexagon of side 9 cm has a charge 5 $\mu C$ at each of its vertices, then electric potential at its centre is ___________ V.
\[\left(k=9 \times 10^9 Nm^2 C^{-2}\right)\]

In the disintegration series  the values of Z and A respectively will be

(a) 92, 236

(b) 88, 230

(c) 90, 234

(d) 91, 234

When the current change from + 2A to – 2A in 0.05 second, an e.m.f. of 8 V is induced in a coil. The coefficient of self-induction of the coil is

(a) 0.1 H

(b) 0.2 H

(c) 0.4 H  

(d) 0.8 H

Assertion : All the radioactive elements are ultimately converted in lead.

Reason     : All the elements above lead are unstable.

(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.