Tag: magnetic effects of electric current

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Questions Related to magnetic effects of electric current

Multiple choice physics magnetic effects of electric current direct current types of current movement of charge

In the direct current:

  1. The direction of current is always positive

  2. The direction of current is always negtive

  3. The direction of current changes constantly

  4. The direction of current is always in the same direction
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

D
Direct current is an electric current generated by the charge carriers (electrons) that are flowing in only one direction. So, the DC current flows only in one direction. DC current is produced be the sources such as batteries, thermocouple, fuel cells, solar cells.

Multiple choice physics magnetic effects of electric current direct current types of current movement of charge

The current in the armature of a motor is reversed every half cycle due to the action of on:

  1. armature

  2. field coil

  3. brush

  4. commutator
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In a DC motor, the commutator acts as a rotary electrical switch that periodically reverses the current direction in the armature winding every half cycle, ensuring continuous rotation in one direction.

Multiple choice physics magnetic effects of electric current direct current types of current movement of charge

What is the voltage of the electricity that is generally supplied to a house ?

  1. $400 V$
  2. $200 V$
  3. $220 V$
  4. $260 V$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Worldwide, many different mains power systems are found for the operation of household and light commercial electrical appliances and lighting. The different systems are primarily characterized by the following.

  • Voltage
  • Frequency
  • Plugs and sockets (receptacles or outlets)
  • Earthing system (grounding)
  • Protection against overcurrent damage (e.g., due to short circuit), electric shock, and fire hazards.
  • Parameter tolerances.
All these parameters vary among regions. The voltages are generally in the range 100 to 240 V. The two commonly used frequencies are 50 and 60 Hz. Single-phase or three-phase power is most commonly used today.
In India, a voltage of nearly 220 volts and a frequency of 50 cycles per second is used.
Hence correct option is option C

Multiple choice physics magnetic effects of electric current direct current types of current movement of charge

In a dry cell

  1. Chemical energy is converted into heat

  2. Electrical energy is converted into electrical energy

  3. Chemical energy is converted into electrical energy

  4. Chemical energy is constant
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A Dry cell is a type of electricity producing chemical cell, commonly used for many home and portable devices , often in the form of batteries. it was developed in 1886 by German scientist Carl Gassner. 

A dry cell  is designed to convert it's chemical energy into electrical energy.
hence option C is correct.

Multiple choice physics magnetic effects of electric current direct current types of current movement of charge

The function ${\sin}^{2}{\omega t}$ represents:

  1. a periodic, but not simple harmonic, motion with a period $2\pi/\omega$
  2. a periodic, but not simple harmonic, motion with a period $\pi/\omega$
  3. a simple harmonic motion with a period $2\pi /\omega$
  4. a simple harmonic motion with a period $\pi /\omega$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Using the identity sin^2(wt) = (1 - cos(2wt)) / 2, the motion is simple harmonic with an angular frequency of 2w, meaning the period is 2pi / (2w) = pi / w.