Tag: magnetic effects of electric current

Questions Related to magnetic effects of electric current

Dry cell is a source of

  1. Direct current

  2. Alternating current

  3. Can be used as direct current source or alternating current source

  4. Cant say


Correct Option: A
Explanation:

Dry cells produces direct current .


Answer-(A)

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


Correct Option: D
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.

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


Correct Option: A

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

  1. $400 V$

  2. $200 V$

  3. $220 V$

  4. $260 V$


Correct Option: C
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

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


Correct Option: C
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.

Secondary cells are also knows as

  1. Electrolyte

  2. Accumulators

  3. Dry cell

  4. All


Correct Option: B
Explanation:

Secondary cells also provide current as a result of chemical reaction, but they can be recharged after use because in these cells, the chemical reaction is reversible.

Which of the following is a source of direct current.

  1. Cell

  2. Electromagnet

  3. Bulb

  4. Switch


Correct Option: A
Explanation:

Source of direct current are the cells. In a cell, the chemical energy changes in to the electrical energy when it sends current in a circuit.

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 $\pi /\omega$


Correct Option: D

The frequency of A.C mains in India is

  1. $30c/s$

  2. $50c/s$

  3. $60c/s$

  4. $120c/s$


Correct Option: B
Explanation:

In India the frequency of A.C current is $50$Hz.

In the direct current

  1. The direction of current is always positive

  2. The direction of current is always negative

  3. The direction of current changes constantly

  4. The direction of current is always in the same direction.


Correct Option: D
Explanation:

In the direct current, the direction of current is always in the same direction.