Tag: physics

Questions Related to physics

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.

An alternating voltage is connected across a series $RLC$ Circuit through an $a.c.$ ammeter. The ammeter reading is the.....

  1. The peak current

  2. The peak current in resonance condition

  3. rms current

  4. zero


Correct Option: B

The outlets in your home provide.

  1. Direct current

  2. Alternating current

  3. Electric discharge

  4. Static Electricity


Correct Option: B
Explanation:

The outlets in our home provide alternating current. All our home appliances work on alternating current.

The .... is a current of constant magnitude flowing in one direction.

  1. Direct current

  2. Alternating current

  3. Electro magnetic induction

  4. All


Correct Option: A
Explanation:

The direct current is a current of constant magnitude flowing in one direction. The source of direct current are the cells.

A cell basically consists of ....... conducting rods.

  1. One

  2. Two

  3. Three

  4. Four


Correct Option: B
Explanation:

The source if direct current are the cells, In cell, the chemical energy changes into the electric energy when it sends current in a circuit. Cell basically consists of two conducting rods, which are called the electrodes.

A secondary cell can provide______  current.

  1. Low

  2. High

  3. Both

  4. None


Correct Option: C
Explanation:

Secondary cells can provide low as well as high current. We use lead accumulator battery in a car as it is capable of giving large current. Low current rechargeable cells are widely used in toys and mobile phones.

What will be the reading of a hot wire voltmeter if it is connected across the terminals of a generator whose voltage wave form is represented by 
$V = 200\sin \omega t + 100\sin 3\omega t + 50\sin 5\omega t$?

  1. 100V

  2. 162 V

  3. 150 V

  4. 200 V


Correct Option: B

Which of the following is wrong?

  1. It is not possible to have electrolysis by a.c.

  2. Ordinary batteries cannot be changed by a.c.

  3. In a circuit containing L, C and R in series across a steady source, poer is dissipated in R, at steady state

  4. For current dirven from a steady source by an ohmic conductor, mean value and r.m.s. value of current will be same


Correct Option: A