## Saturday, 27 November 2021

### CURRENT ELECTRICITY: 10+2 PHYSICS MCQ ON CURRENT ELECTRICTY

CURRENT ELECTRICITY: 10+2 PHYSICS MCQ ON CURRENT ELECTRICTY

Q1. Which has greater resistance ?

• (a) Voltmeter has more resistance
• (b) Millivoltmeter has more resistance
• (c) Both have same resistance
• (d) Depends on size of meter coil.

Q2. To reduce the range of voltmeter, its resistance is to be reduced. A voltmeter has a resistance G and range V. What resistance connected in parallel will convert it into a voltmeter of range V/n

• a)  nG
• (b) (n + 1) G
• (c)(n-1) G
• (d) none of the above

Q3. The sensitivity of a galvanometer does not depend upon

• (a) a very strong magnetic field in the permanent magnet
• (b) the current it measures
• (c) a very thin, weak suspension
• (d) a large number of turns in the coil

Q4. Out of  the following an ideal voltmeter is

• (a) moving coil voltmeter
• (b) voltameter
• (c) an electrometer
• (d) hot wire voltmeter

Q5. The electric cell is a device to obtain

• (a) electric charge
• (b) electric force
• (c) electrons
• (d) electric energy from chemical energy

Q6. Constantan wire is used for making standard resistance, because it has

• (a) high melting point
• (b) low specific resistance
• (c) high specific resistance
• (d) negligible temperature coefficient of resistance.

Q7. At temperature 0 K, the germanium behaves as

• (a) conductor
• (b) insulator
• (c) super-conductor
• (d) ferromagnetic

Q8. If temperature is decreased, then relaxation time of electrons in metals will

• (a) increase
• (b) decrease
• (c) fluctuate
• (d) remains constant.

Q9. Consider the following two statements.

(A) Kirchoff's junction law follows from conservation of charge.
(B) Kirchoff's loop law follows from conservative nature of electric field.

• (a) Both A and B are correct
• (b) A is correct but B is wrong
• (c) B is correct but A is wrong
• (d) Both A and B are wrong.

Q10. Wheatstone bridge is used to measure

• (a) potential
• (b) e.m.f.
• (c) current
• (d) resistance

Q11. Why is the Wheatstone bridge better than the other methods of measuring

resistances ?

• (a) It does not involve Ohm's law
• (b) It is based on Kirchoff's law
• (C) It has four resistor arms
• (d) It is a null method

Q12. suppose in an  experiment of Wheatstone's bridge, the positions of cells and galvanometer are interchanged, then balance point will

• (a) change
• (b) remain unchanged
• (c) depend on the internal resistance of cell and resistance of cell and resistance of galvanometer.
• (d) none of these.

Q13. Drift velocity is due to :

• (a) Applied electric field over a given distance
• (b) Random motion of electrons
• (c) Random motion of holes
• (d) Rcombination of holes and electrons

Q14. Mobility is always............

• (a) positive
• (b) negative
• (c) both
• (d) none

Q15. More is drift velocity   ......will be the current

• (a) Less
• (b) More
• (c) Equal
• (d) None.

Q16. Resistance of a conductor depends directly upon :

• (a) Pressure
• (b) Area
• (c) length
• (d) None.

Q17. With the increase in area of cross-section, the resistance of the conductor

• (a) increase
• (b) decrease
• (c) remains same
• (d) increase 5 times of original value.

Q18. Resistivity of a conductor varies with temperature and

• (a) Nature of material
• (b) area
• (c) length
• (d) None

Q19. Resistivity for semiconductor

• (a) Decrease with rise in temperature
• (b) increase with temperature rise
• (c) no change
• (d) None

Q20. Resistance has SI unit as

• (a) ohm meter
• (b) ohm
• (c) mho
• (d) all of these

Q21. Which of the following have +ve temperature coefficient of resistivity.

• (a) Semiconductor
• (b) Metals
• (c) Alloys
• (d) Insulators

Q22. What is the nature of temperature coefficient of resistivity for conductors.

• (a) Always positive
• (b) Always negative
• (C) Can have positive value or negative value
• (d) Always zero.

Q23. How to read colour bands on Resistors ?

• (a) Right to left
• (c) from both sides
• (b) Left to Right
• (d) All are correct.

Q24.The first two bands on the resistors are ..............

• (a) Two digits
• (b) Decimal Multiplier
• (c) Tolerance
• (d) All are incorrect.

Q25. What colour is a 340 kΩ resistor with 5% tolerance resistive

• (a) Orange, Yellow and Yellow with Gold
• (b) Orange, Green and Yellow with Gold
• (c) Orange, Blue and Orange with Gold
• (d) Orange, Yellow and Green with Gold.

Q26.It is preferable to connect bulbs in series or in parallel ?

• (a) Series
• (b) Parallel
• (c) both
• (d) None

Q27. Batteries are generally connected in

• (a) Series
• (b) Parallel
• (c) both
• (d) None.

Q28. The combined resistance of  12Ω   and 20Ω connected in series is

• (a) 61Ω
• (b) 32Ω
• (c) 18Ω
• (d) 41Ω

Q29. S.I. unit of electro motive force (emf)  is

• (a) Coulomb
• (b) Ampere
• (c) Volt
• (d) Coulomb

Q30. Electromotive force.........potential difference

• (a) may be equal to
• (b) may be greater than
• (c) both (a) and (b)
• (d) None of these

Q31. The potential difference depends on the..................flowing through conductor

• (a) Current
• (b) Voltage
• (c) both
• (d) None

Q31. Electric current is a..... ..quantity

• (a) Scaler
• (b) Vector
• (C) Tensor
• (d) None of above

Q32. S.I. unit of Electric current is

• (a) Coulomb
• (b) Ampere
•  (c) Coulomb
• (d) Tesla

Q33. Through a conductor electric current is thought to be a movement of

• (a) ions
• (b) orbits
• (c) Electrons
• (d) Protons

Q34. Fill in the blank : 1 Ampere =

• (a) 3 x 10⁹ stat ampere
• (b) 3 x 10¹⁰ stat ampere
• (c) 3 x 10¹¹stat ampere
• (d) 3 x 10 stat ampere

Q35. Number of  electrons passes in one second when current is 1 Ampere

• (a) 5.26 x 10¹⁸
• (b) 6.25 10²⁸
• (c) 2.96 x 10¹⁶
• (d) 8.65 x 10⁹

Q36. If potential difference 'V' applied across conductor is increased to 3V, how will the drift velocity of electron change ?

• (a) Drift velocity becomes tripled
• (b) Drift velocity becomes doubled
• (c) Remains same
• (d) Drift velocity becomes four times

Q37. What is mobility ?

• (a) Ease of carrier drift
• (b) Ease of current flow
• (d) Ease of movement

Q38. The relaxation time in conductors:

• (a) Increases with increase in temperature
• (b) Decreases with increase in temperature
• (c) It does not depend on temperature
• (d) may increase or decrease depends on nature of conductors

Q39. Internal resistance depends on

• (a) Nature of electrolyte
• (b) Nature of electrodes
• (c) Both (a) and (b)
• (d) Pressure

Q40. To draw maximum current from a combination of cells how should the cells be grouped ?

• (a) Series
• (b) Parallel
• (c) Mixed
• (d) Depends upon the relative value of external and internal resistance.

Q41. Two cells of e.m.f. 1.25 V and 0.75 V and internal resistance of 2Ω  and 12Ω  respectively are connected in series, Find the effective E.M.F.

• (a) 2V
• (b) 3V
• (c) 5V
• (d) 10V