An electric heating element consumes 500 W, when connected to a 100 V line. If the line voltage becomes 150 V, the power consumed Will be:
  • 500 W
  • 750 W
  • 1000 W
  • 1125 W
A uniform w ire connected across a supply produces heat H per second. If wire is cut into three equal parts and all the parts are connected in parallel across the same supply, the heat produced per second will be :
  • \(\frac{H}{9}\)
  • 9 H
  • 3 H
  • \(\frac{H}{3}\)
In India electricity is supplied fordomestic use at 220 V. It is supplied at 110 V in U.S.A. If the resistance of a 60 W bulb use in India is R. the resistance of a 60 W bulb for use in USA will be:
  • 2 R
  • R
  • R/2
  • R/4
Two bulbs 25 W, 220 V and 100 W, 220 V are given. Which has higher resistance?
  • 25 W
  • 100 W
  • both bulbs have equal resistance
  • resistance of bulbs can not be compared
Potentiometer measures the potential difference more accurately than a voltmeter because:
  • It has a wire of high resistance
  • It has a wire of low resistance
  • It does not draw current from external circuit
  • It draws heavy current from external circuit
In a Wheatstone bridge, the resistance each arm is 10 Ω. If the resistance galvanometers is also 10 Ω, then effective resistance of the bridge will be :
  • 40 Ω
  • 20 Ω
  • 10 Ω
  • 5 Ω
The resistance of an aluminium wire is/i. It is stretched to /i times its original length. Its new resistance will be :
  • nr
  • n²r
  • \(\frac{n^2}{r}\)
  • \(\frac{r}{n^2}\)
A wire P is half the diameter and half the length of a wire Q of similar material. The ratio of resistances of P to that 0 is:
  • 4 : 1
  • 8 : 1
  • 2 : 1
  • 1 : 2
What is the resistance across A and B in the network in Fig.?
  • R
  • 2 R
  • \(\frac{R}{2}\)
  • 6 R
When the wires are connected in parallel, the heat produced in the thinner wire is H1 and that in the thicker wire is H2 Then:
  • H1 = H2
  • H1 < H2
  • H1 > H2
  • H1 ≥ H2
Two equal resistors are connected in series across a battery and consume a power of P. If these are connected in parallel, then the' power consumed will be:
  • 2P
  • 4P
  • \(\frac{p}{4}\)
  • P
Thermo electricity was discovered by:
  • Joule
  • Peitier
  • Thomson
  • Seebeck
Thermo emf is the order of:
  • 10 V
  • 10-3 V
  • 10-6 V
  • 10-12 V
In the following figure represents a balanced Wheatstone bridge circuit. What is the value of X?
MCQ Questions for Class 12 Physics Chapter 3 Current Electricity with Answers
  • 15 Ω
  • 20 Ω
  • 25 Ω
  • 30 Ω
The charge flowing in a conductor varies with time as :
q = αt \(\frac{1}{2}\) βt² + \(\frac{1}{6}\) γt³
Where α, β, γ are positive constants. Then the initial current (l) is given by the condition :
  • l = α
  • l = α²
  • l = α-1
  • None of these
In following figure shows currents in a part of electrical circuit, then the value of/(in ampere) is given by :
MCQ Questions for Class 12 Physics Chapter 3 Current Electricity with Answers
  • 0.3 A
  • 0.5 A
  • 1.3 A
  • None of these
In questions 135, when the wires are connected in series, the heat produced in the thinner wire is H1 and that in the thicker wire is H2. Then :
  • H1 = H2
  • H1 < H2
  • H1 > H2
  • None of the above
0 h : 0 m : 1 s

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