A 40 W bulb is connected in series with a room heater. If now 40 W bulb is replaced by 100 W bulb, the heater output will__________

Related Mcqs:

1. When resistance element of a heater fuses and then we reconnect it after removing a portion of it, the power of the heater will___________?

   A. decrease
   B. increase
   C. remain constant
   D. none of the above

2. A nichrome wire used as a heater coil has the resistance of 2 £2/m. For a heater of 1 kW at 200 V, the length of wire required will be_____________?

   A. 80 m
   B. 60 m
   C. 40 m
   D. 20 m

3. A light bulb draws 300 mA when the voltage across it is 240 V. The resistance of the light bulb is___________?

   A. 400 Q
   B. 600 Q
   C. 800 Q
   D. 1000 Q

4. Four wires of same material, the same cross-sectional area and the same length when connected in parallel give a resistance of 25 Q. If the same four wires are connected is series the effective resistance will be________?

   A. 100 Ω
   B. 200 Ω
   C. 300 Ω
   D. 400 Ω

5. Two lamps 100 W and 40 W are connected in series across 230 V (alternating). Which of the following statement is correct ?

   A. 100 W lamp will glow brighter
   B. 40 W lamp will glow brighter
   C. Both lamps will glow equally bright
   D. 40 W lamp will fuse

6.  If P is the power of a star connected system then what will be power of an equivalent delta connected system?

   A. P
   B. 3P
   C. P/3
   D. None of the above

   Updated by: muhammad rahim

7. When current flows through heater coil it glows but supply wiring does not glow because______________?

   A. current through supply line flows at slower speed
   B. supply wiring is covered with insulation layer
   C. resistance of heater coil is more than the supply wires
   D. supply wires are made of superior material

8. Two resistors are said to be connected in series when___________?

   A. same current passes in turn through both
   B. both carry the same value of current
   C. total current equals the sum of branch currents
   D. sum of IR drops equals the applied e.m.f.

9. The four bulbs of 40 W each are connected in series swift a battery across them, which of the following statement is true_______________?

   A. The current through each bulb in same
   B. The voltage across each bulb is not same
   C. The power dissipation in each bulb is not same
   D. None of the above

10. Two resistances Rl and Ri are connected in series across the voltage source where Rl>Ri. The largest drop will be across______________?

    A. Rl
    B. Ri
    C. either Rl or Ri
    D. none of them