DC Circuit MCQ Job Interview Exam Higher Study Admission Questions Answers part5

DC Circuit MCQ Job Interview Exam Higher Study Admission Questions Answers part5

41.    Three equal resistors connected in series across a source of e.m.f together dissipate 10 W. What would be the power dissipated if the same resistors are connected in parallel across the same source of e.m.f? 90W

42.In a circuit, two cells of 1.5 V and 2 V e.m.f. having internal resistances of 1Ω and 2 Ω respectively are connected in parallel so as to send current in the same direction through an external resistance of 5 Ω. The circuit current is 5/17 A.

43.  A standard 4o W tube light is in parallel with a room heater and both are connected to main supply line. What will happen when light is switched off?  The heater output will remain same.

 

DC Circuit MCQ Job Interview Exam Higher Study Admission Questions Answers part4

DC Circuit MCQ Job Interview Exam Higher Study Admission Questions Answers part4


1.Four cell, each of internal resistance 1 Ω, are connected in parallel. The battery resistance will be  0.25 Ω.

2.The current in a coil of resistance 90 Ω is to be reduced by 90%. What value of resistance should be connected in parallel with it?  10 Ω.

3.In order to get maximum current in series-parallel grouping of cells, the external resistance should be equal to the total internal resistance of the battery.

4.Two equal resistance are connected in series across a certain supply. If the resistances are now connected in parallel, the power produced will become four times.
 

5. Voltmeters V1 and V2 are connected in series across a d.c. line. The voltmeter  V1 reads 80 V and has per volt resistance of 200 Ω while V2 has a total resistance of 32 kΩ. The line voltage is  240 V.

6. A wire has a resistance of 6 Ω. It is bent in the form of an equilateral triangle. The effective resistance between any two corners of the triangle is  4/3 Ω.

7. Two similar cells whether joined in series or in parallel have the same current through an external resistance of 2 Ω. The internal resistance of each cell is 2 Ω.

8.When resistance are connected in parallel, the current divides itself in inverse ratio of resistances.

      9.When a d.c. battery of e.m.f E and internal resistance r delivers maximum power to an external resistance R, the ratio r/R is 1:1.

     

     10.   Two bulbs rated at 25 W, 110 V and 100 W, 110 V are connected in series to a 220 V supply. What will happen to the circuit?  25 W bulb will burn out. 

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