Ohm's Law Multiple choice Question (Electrical Mcqs) and Answer Part 5

                   Electrical Engineering Objective Question and Answer 

91- 40 W bulb A will be least bright when   

        (A) only keys k1 and k2 are open  

        (B) key k1 is closed, k2 and k3 are open 

        (C) key k1 and k2 are closed and k3 is open  

        (D) all the keys are closed 

       Answer: (A)

92- The power consumption of the circuit will be maximum  

        (A) laminated silicon steel core 

        (B)small air gap 

        (C) fewer rotating parts 

        (D) large leakage flux 

       Answer: (A)

93- Which of the following lamp will have least resistance at room temperature  

        (A) 200 W, 220 V

        (B) 100 W , 220 V

        (C) 60 W , 220 V

        (D) 25 W , 220 V 

       Answer: (A)

 94 -Filaments of electric bulb are usually made of

        (A) Nichrome 

        (B) Tungsten 

        (C) Copper  

        (D) Carbon  

       Answer: (B)

    95- The value of supply voltage for 500 W 5 ohm load is   

        (A) 500 V

        (B) 100 V

        (C) 50 V

        (D) 10 V 

       Answer: (C)

96- Which resistor will be physically larger in size?  

        (A) 10 ohm , 50 W

        (B) 100 ohm , 10 W

        (C) 1 k ohm , 1 W

        (D)  10 Mega ohm , 1/2 W

       Answer: (A)

97- Four resistances R 1 , R 2 , R 3 and R 4 are connected in series against 220 V supply. The resistances are such that R 1 > R 2 > R 3 > R 4 . The least power consumption will be in 

        (A) resistor R 1 

        (B) resistor R 2

        (C) resistor R 3 

        (D) resistor R 4  

       Answer: (D)

98- 100 resistors of 100 ohms each are connected in parallel. their equivalent resistance will be    

        (A) 10,000 ohms  

        (B) 100 ohms 

        (C) 1 ohm  

        (D) 1/10,000 ohm 

       Answer: (C)

99- For a fixed supply voltage , the current flowing through a conductor will decrease , when 

        (A) cross-sectional area of conductor is increased  

        (B) length of conductor is increased 

        (C) length of conductor is reduced  

        (D) cross-sectional area is increased and length is decreased 

       Answer: (B)

 100 - When current flows through heater coil it glows but supply wiring does not glow because  

        (A) supply wiring is covered with insulation layer 

        (B) current through supply line flows at slower speed

        (C) supply wires are made of superior material  

        (D) resistance of heater coil is more than that supply wire 

       Answer: (D)

  The Q 81 to Q 83 belong to the given fig.

      

     81- The value of current I in the given circuit is

        (A) 10 A

        (B) 15 A 

        (C) 20 A

        (D) 25 A

       Answer: (D)

     82- The combined resistance of the circuit is 

        (A) 10 ohms 

        (B) 5 ohms

        (C) 4 ohms

        (D) 2 ohms 

       Answer: (C)

     83- Total power dissipated in the circuit is  

        (A) 2.5 kW 

        (B) 5 kW

        (C) 7.5 kW 

        (D) 10 kW 

       Answer: (B)

      84- A 100 W bulb is connected in series with a room heater of 750 W. what will happen if the bulb is replaced by a 60 W bulb ?

        (A) Heater output will increase 

        (B) Heater output will decrease 

        (C) Heater output will remain unchanged 

        (D) Bulb will not glow 

       Answer: (A)

        85- An immersion rod heats a bucket of water in 15 minutes. In order that the water should boil in 10 minutes 

        (A) length of heating element of the rod should be increased  

        (B) length of heating element of rod should be reduced 

        (C) supply voltage should be reduced 

        (D) heating element of larger diameter should be used 

       Answer: (B)

      86- A stamp of 100 W at 200 V is supplied current 100 volts. It will be equivalent to the lamp of      

        (A) 50 W 

        (B) 40 w

        (C) 25 W

        (D) 10 W

       Answer: (D)

      87- Two electric bulbs of 100 W, 200 v are put in series and the combination is supplied 100 v. The power consumption of each bulb will be   

        (A) 100/2 W 

        (B) 100/4 W

        (C) 100/8 W

        (D) 100/16 W

       Answer: (B)

     Question 88 to 91 refer to Fig. 13

        

        

      88- Three lamps are in circuit as shown in Fig. 13. The lamp of 100 W will have maximum brightness when

        (A) key K1 is closed , k2 is open and k3 is closed

        (B) k1 is open, k2 is closed and k3 is open 

        (C) k1 is open , k2 is closed and k3 is closed  

        (D) k1 is closed, k2 is open and k3 is also open

       Answer: (B)

       89- if switches k1 and k3 are open and k3 is closed   

        (A) 100 W lamp sill glow brighter than 40 W lamp

        (B) 40 W lamp will glow brighter than 100 w lamp

        (C) Both will glow at their full brightness 

        (D) Both will glow at less than their full brightness 

       Answer: (B)

       90- The magnetizing current of a transformer is usually small because it has  

        (A) laminated silicon steel core 

        (B)small air gap 

        (C) fewer rotating parts 

        (D) large leakage flux 

       Answer: (D)