Practice Questions answers set 1 - general science mcq Online Quiz (set-1) For All Competitive Exams
Q-1) Which impurity is doped in Si to form n-type semiconductors?
(a)
(b)
(c)
(d)
Because As is pentavalent impurity.
Q-2) At absolute zero, Si acts as
(a)
(b)
(c)
(d)
Semiconductors are insulators at room temperature.
Q-3) Fuse wire is made of
(a)
(b)
(c)
(d)
Q-4) The forbidden gap in the energy bands of germanium at room temperature is about
(a)
(b)
(c)
(d)
Δ$E_{g(Germanium)}$ = 0.67 eV.
Q-5) Consider the following statements regarding a motor car battery. - The voltage is usually 12V.
- Electrolyte used is hydrochloric acid.
- Electrodes are lead and copper.
- Capacity is expressed in ampere-hour.
Which of the above statements are correct?
(a)
(b)
(c)
(d)
Q-6) Conductivity increases in the order of
(a)
(b)
(c)
(d)
Silver is the best conductor of electricity.
Q-7) The permanent magnet is made from which one of the following substances?
(a)
(b)
(c)
(d)
Q-8) Whenever, current is changed in a coil, an induced e.m.f. is produced in the same coil. This property of the coil is due to
(a)
(b)
(c)
(d)
Q-9) Metals getting magnetised by orientation of atomic magnetic moments in external magnetic field are called
(a)
(b)
(c)
(d)
In paramagnetic metals, magnetism is acquired by orientation of atomic dipoles.
Q-10) Potential at any point inside a charged hollow sphere
(a)
(b)
(c)
(d)
As, E = $ -{dV}/{dr}$ or, O= $- {dV}/{dr}$
Because electric field inside a charged hollow sphere is zero. or, v = constant