An X-ray beam can be deflected by :
- A.An electric field
- B.A magnetic field
- C.An electric as well as a magnetic field
- D.Neither an electric field nor a magnetic field
Correct answer
Explanation
The correct answer is D, Neither an electric field nor a magnetic field. X-rays are electromagnetic waves made of photons, which carry no electric charge, so electric and magnetic fields cannot bend them.
An electric field pushes on a body only if it has charge, and a magnetic field pushes on it only if it is a moving charge. Beams of electrons or alpha particles therefore curve in such fields, but X-rays, like light and gamma rays, travel straight through. Wilhelm Röntgen discovered X-rays in 1895 and found that they were not deflected by a magnet, which showed they were not a stream of charged particles.
A is wrong: an electric field acts only on charged particles, and an X-ray photon has no charge.
B is wrong: a magnetic field deflects only moving charges, such as cathode rays.
C is wrong: since neither field alone acts on X-rays, the two together cannot deflect them either.
Exam tip: alpha and beta rays bend in electric and magnetic fields; gamma rays and X-rays do not, because they are uncharged electromagnetic waves.
Practice Questions
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- C.caustic soda
- D.nitric acid
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Read the full explanation →