Ohm's Law Multiple choice Question (Electrical Mcqs) and Answer Part 4

                       Electrical Engineering Objective Question and Answer 

61- Low resistance can be accurately measured by   

        (A) Kelvin bridge 

        (B) Wheat stone bridge 

        (C) Wein's bridge 

        (D) none of above 

       Answer: (A)

       62- A heating element of hot plate on an electric cooking range draws 12 amperes from 240 volts mains. how many kwh of energy will be consumed in one hour and 15 minutes

        (A) 1.2

        (B) 3.2

        (C) 6

        (D) 7.2

       Answer: (B)

       63- Temperature coefficient of resistance is expressed in terms of 

        (A) ohms/ohms°C

        (B) mhos/ohm°C

        (C) mhos/°C

        (D) ohms/°C 

       Answer: (A)

     64- if Rt is the resistance of a coil of copper at t C and Rt is the resistance at Tc and also the resistance temperature coefficient of copper per degree centigrade at 0 C is 1 / 234.45, then Rt/RT is given by      

  

       Answer: (C)

      65- Resistivity is usually expressed in terms of 

        (A) mho

        (B) ohm/ °C

        (C) ohm/ cm - square 

        (D) ohms/ cm - cube

       Answer: (D)

       66- Which material is expected to have least resistivity ?

        (A) Copper 

        (B) Lead 

        (C) Mercury 

        (D) Zinc 

       Answer: (A)

       67- The shunt winding of a motor has a Resistance 0f 85 ohm at 22 C. when the motor runs at full load , its resistance increases to 100 ohms. The Resistance temperature coefficient of winding per 0 C is 0.004. The rise in temperature of the winding will be nearly       

        (A) 20 °C

        (B) 50 °C 

        (C) 70 °C 

        (D) 100 °C

       Answer: (C)

   68- The resistance temperature coefficient is defined as    

        (A) increase in resistance per degree centigrade 

        (B) decrease in resistance per degree centigrade 

        (C) the ratio of increase in resistance per degree centigrade to the resistance at 0 C 

        (D) the ration of increase in resistance per degree centigrade to the resistance at 0C 

       Answer: (C)

     69- Two coils connected in series have resistance of 600 ohms and 300 ohms and temperature coefficient of 0.1% and 0.4% respectively. The resistance of the combination at 50 C  will be    

        (A) 1050 ohms

        (B) 1001 ohms

        (C) 1600 ohms

        (D) 900 ohms 

       Answer: (D)

     70- A 100 W, 200 V filament lamp has operating temperature of 2000 C. The filament material has resistance temperature coefficient of 0.005 at 0 C per  C. The current taken by the lamp at the instant of switching with 200 V supply with filament temperature of 20 C will be     

        (A) 1 A 

        (B) 3 A

        (C) 5 A 

        (D) 10 A 

       Answer: (C)

      71- A fuse is always installed in a circuit is 

        (A) Series 

        (B) Parallel 

       Answer: (A)

      72- The rating of fuse wire is expressed in terms  

        (A) ohms

        (B) Mhos  

        (C) Amperes 

        (D) Watts

       Answer: (C)

       73- Which of the following material is not used as fuse material ?

        (A) Silver 

        (B) Copper 

        (C) Aluminum  

        (D) carbon 

       Answer: (D)

      Questions 74 to 78 refer to Fig. 11

       

     74-  The Voltage drop across the resistor 9 ohm will be 

        (A) 18 V

        (B) 12 V

        (C) 9 V 

        (D) 6 V

       Answer: (A)

      75 - The Voltage drop will be least in which resistor   

        (A) 2 ohm 

        (B) 3 ohm

        (C) 6  ohm

        (D) 3 ohm and 6 ohm

       Answer: (D)

      76- The current in the 6 ohm resistor will be 

        (A) 1 A

        (B) 2 A

        (C) 3 A 

        (D) 4 A

       Answer: (C)

      77- The ratio of power dissipated in the circuit ADB to that in circuit ABC will be   

        (A) 1 

        (B) 1.5

        (C) 0.67 

        (D) 2

       Answer: (B)

        78- Total power dissipated in an electrical  circuit is    

        (A) 80 W

        (B) 100 W

        (C) 120 W

        (D) 150 W

       Answer: (C)

      79- The fuse has current carrying capacity due to   

        (A) Cross-sectional area

        (B) length 

        (C) material

        (D) all of the above 

       Answer: (D)

     80- As from fuse law , the current carrying capacity is proportional to

        (A) 1/diameter

        (B) (diameter)^3/2

        (C) 1/diameter  

        (D) 1/(diameter)^2 

       Answer: (B)