Answer / vivek anand

Let us understand by taking some example.

let say heater is of 500w and 250v

Bulb 100w and 250v

now, calculate the R

P = V^2/R

SO

R = V^2/P

R1 (heater) = 250 * 250 /500 = 125 ohm

R2 (bulb)= 250 * 250 /100 = 625 ohm

Now, as the question says, they are connected in series, lets find out the current drawn by the circuit

I = V/R

LET THE CIRCUIT CONNECTED WITH 250V SUPPLY

I = 250/(125+625) (R ARE IN SERIES)

I = 0.33A

THIS IS THE AMOUNT OF CURRENT DRAWN BY CIRCUIT IN CONFIGURATION 1.

power of heater = I^2*R*T (TAKE T = 1 hr)

P = 0.33*0.33*125*60*60 = 495 ~ 500w

Now, replace 100w bulb with 40w bulb

R2 (bulb)= 250 * 250 /40 = 1562.5 ohm

New Resistance of circuit will be

R'= 125 + 1562.5 = 1687.5

**NOTE "THE CURRENT IN SERIES IS ALWAYS SAME" and "THE CURRENT DRAWN BY THE CIRCUIT DEPENDS ON LOAD (RESISTANCE)"

In this case we change the load form 750 ohm to 1687.5 ohm, so definitely the current drawn will change.

Now, I' = 250/1687.5 = 0.148 A

now this current will same in the circuit for both bulb and heater bcoz they are in series.

NEW POWER OF HEATER

P = 0.15*0.15*125*60*60 = 101.25

so

OUTPUT DECREASES

Answer / sunil shrivastava

decrease

Answer / sivakumar

out put of the heater decreases because 100watts bulb takes more power then 40 watts bulb. 100 watts produces more heat then 40 watts bulb.

Answer / sarfraj palegar

in this condition heater output will increases
lets take a example and heater resistance X ohms
voltage =current*resistance
in first condition resistance in cercuite is high thats why
current low compare to 2nd condition
in 2nd condition this higher current passes throug circuit
as per formula of heat
H=I2RT
heat output will increases

Answer / yogesh kumar

remains same

Answer / syed ali raza naqvi

output same because in series current is same.in every
point and voltages different.

Answer / roopesh

P=(I^2)R

In series circuit the current is same. So in series circuit power(p) is proportional to resistance(r), therefore 100w bulb has more resistance compare to 40w bulb.

Answer / alok das

If the 100w buld is replaced by a 40w buld then the output
of the heater is increase.

Answer / erick atienza

Since the connection is in series, it will increase because the the current will increase.

what is impedence in transformer

2 Answers  

where does the unbalanced current flow in the delta circuit

3 Answers  

what happens if number of poles in stator and rotor windins of slip ring induction motor are not same. Will it rotate near to the synchronus speed defined by stator?

1 Answers   GATE,

A 3 phase motor, 440 voltage, induction motor. If we take out rotor from motor and if we give supply 440 volt to stator then what happens?????

20 Answers  

what will happen if multimeter(selector switch at DC voltage) and terminal at current is connected to DC supply?

0 Answers  

If more than rated DC voltage appears across trip coil of the breaker, what will happen? e.g. in 110V DC circuit system, if voltage across battery terminal showing 121 V

0 Answers  

WE HAVE A LOAD OF 55KW MOTOR ITS VOLTS 380 3PH AND ITS TAKING 100AMPS (ITS FULL LOAD IS 105AMPS)AND ITS CABLE IS 4CX50SQMM ,NOW ITS GETTING ABNORMAL HEATUP IN CABLE,PLZ TELL WHY ITS HEAT-UP?(CABLE LENGTH IS 15 METERS ONLY)

10 Answers  

what is ACB and its function?

3 Answers  

What is the difference between resistance grounding system and resistance earthing system?

0 Answers  

What is the effect of solar radiation on the design of an Isolated Phase Busduct?

0 Answers   Exide, Punj Lloyd Ltd,

What is a advantage of Self Reset Lockout ? On Fault breaker get trip & fault no longer exist then self reset lockout how inform us?

0 Answers   Bhad Engineers,

what parameters are should nessary for control technic dc drive(in rolling mills)?

0 Answers   TATA,