Physics Mcqs Notes for 12th Class Exam
Resistivity of a wire depends on :
(C) cross section area
(D) none of the above.
2. When n resistances each of value r are connected in parallel, then
resultant resistance is x. When these n
resistances are connected in series,
total resistance is:
(C) x / n
(D) n2 x
3. Resistance of a wire is r ohms. The wire is stretched to double its length,
then its resistance in ohms is:
(A) r / 2
(B) 4 r
(C) 2 r
(D) r / 4.
4. Kirchhoff’s second law is based on law of conservation of:
5. The diameter of the nucleus of an atom is of the order of :
(A) 10 -31 m
(B) 10 -25 m
(C) 10 -21 m
(D) 10 -14m.
6. The mass of proton is roughly how many times the mass of an electron?
7. The charge on an electron is known to be
1.6 x 10-19 coulomb. In a circuit
the current flowing is 1 A. How many
electrons will be flowing through the
circuit in a second?
(A) 1.6 x 1019
(B) 1.6 x 10-19
(C) 0.625 x 1019
(D) 0.625 x 1011
8. Two bulbs marked 200 watt-250 volts and 100 watt-250 volts are
joined in series to 250 volts supply.
Power consumed in circuit is:
(A) 33 watt
(B) 67 watt
(C) 100 watt
(D) 300 watt.
9. Ampere second could be the unit of:
10. Which of the following is not the same as watt?
(C) amperes x volts
(D) ( amperes )2 x ohm.
11. One kilowatt hour of electrical energy is the same as:
(A) 36 x 105 watts
(B) 36 x 10s ergs
(C) 36 x 105 joules
(D) 36 x 105 B.T.U.
12. An electric current of 5 A is same as:
(A) 5 J / C
(B) 5 V / C
(C) 5 C / sec
(D) 5 w / sec.
13. An electron of mass m kg and having a charge of e coulombs travels
from rest through a potential
difference of V volts. Its kinetic energy
will be: (A) eV Joules
(B) meV Joules
(C)me / V Joules
(D)V / me Joules.
14. The value of the following is given by 100 (kilo ampere ) x ( micro
ampere ) 100 milli ampere * 10
(A) 0.001 A
(B) 0.1 A
(C) 1 A
15. A circuit contains two un-equal resistances in parallel:
(A) current is same in both
(B). large current flows in larger
(C). potential difference across each is
(D). smaller resistance has smaller