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

Related Mcqs:

1. 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

2. 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__________

   A. decrease
   B. increase
   C. remain same
   D. heater will burn out

3. The resistance of a parallel circuit consisting of two branches is 12 ohms. If the resistance of one branch is 18 ohms, what is the resistance of the other ?

   A. 18 Q
   B. 36 Q
   C. 48 Q
   D. 64 Q

4. 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

5. The resistance of a conductor of diameter d and length l is R Ω. If the diameter of the conductor is halved and its length is doubled, the resistance will be

   A. R Ω
   B. 2R Ω
   C. 4R Ω
   D. 8R Ω

6. The resistance of a copper wire 200 m long is 21 Q. If its thickness (diameter) is 0.44 mm, its specific resistance is around_______________?

   A. 1.2 x 10~8 Q-m
   B. 1.4 x 10~8 Q-m
   C. 1.6 x 10″”8 Q-m
   D. 1.8 x 10″8 Q-m

7. 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

8. If a wire conductor of 0.2 ohm resistance is doubled in length, its resistance becomes______________?

   A. 0.4 ohm
   B. 0.6 ohm
   C. 0.8 ohm
   D. 1.0 ohm

9. The hot resistance of the bulb’s filament is higher than its cold resistance because the temperature co-efficient of the filament is___________________?

   A. zero
   B. negative
   C. positive
   D. about 2 ohms per degree

10. Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be_____________?

    A. 160 ohms
    B. 80 ohms
    C. 20 ohms
    D. 10 ohms