Current Electricity

31. If a parallel circuit is opened in the main line, the current

  1. increases in the branch of the lowest resistance
  2. increases in each branch
  3. is zero in all branches
  4. is zero in the highest resistive branch

Correct answer: (C)
is zero in all branches

32. If a wire conductor of 0.2 ohm resistance is doubled in length, its resistance becomes

  1. 0.4 ohm
  2. 0.6 ohm
  3. 0.8 ohm
  4. 1.0 ohm

Correct answer: (A)
0.4 ohm

33. If the efficiency of a machine is to be high, what should be low?

  1. Input power
  2. Losses
  3. True component of power
  4. kWh consumed

Correct answer: (B)
Losses

34. If/, R and t are the current, resistance and time respectively, then according to Joule's law heat produced will be proportional to

  1. I2Rt
  2. I2Rf
  3. I2R2t
  4. I2R2t*

Correct answer: (A)
I2Rt

35. In a circuit a 33 Q resistor carries a current of 2 A. The voltage across the resistor is

  1. 33 V
  2. 66 v
  3. 80 V
  4. 132 V

Correct answer: (B)
66 v

36. In a lamp load when more than one lamp are switched on the total resistance of the load

  1. increases
  2. decreases
  3. remains same
  4. none of the above

Correct answer: (B)
decreases

37. In a series circuit with unequal resistances

  1. the highest resistance has the most of the current through it
  2. the lowest resistance has the highest voltage drop
  3. the lowest resistance has the highest current
  4. the highest resistance has the highest voltage drop

Correct answer: (D)
the highest resistance has the highest voltage drop

38. In an electric kettle water boils in 10 m minutes. It is required to boil the boiler in 15 minutes, using same supply mains

  1. length of heating element should be decreased
  2. length of heating element should be increased
  3. length of heating element has no effect on heating if water
  4. none of the above

Correct answer: (A)
length of heating element should be decreased

39. In the case of direct current

  1. magnitude and direction of current remains constant
  2. magnitude and direction of current changes with time
  3. magnitude of current changes with time
  4. magnitude of current remains constant

Correct answer: (A)
magnitude and direction of current remains constant

40. Insulating materials have the function of

  1. preventing a short circuit between conducting wires
  2. preventing an open circuit between the voltage source and the load
  3. conducting very large currents
  4. storing very high currents

Correct answer: (B)
preventing an open circuit between the voltage source and the load

Previous
Page 4 of 11
Next
Copyright © EngineeringMCQ.com