Tag: physics

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Questions Related to physics

Multiple choice physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

Which one does not work on principles of resonance?

  1. T.V

  2. Radio

  3. Microwave oven

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

Resonance in an electrical circuit is a phenomenon in which the inductive reactance and the capacitive reactance become equal and cancel each other.

As a result, the impedance of the circuit becomes the least and maximum current flows through the circuit. This happens only at a particular frequency of the AC power supply, known as resonant frequency. 
All the devices except bulb work on this principle. The circuit in them is tuned in order to make their resonant frequency matching with the desired one. This is done by adjusting the values of the inductor or the capacitor.
In a bulb, there is only pure resistance and no reactive component. There is no question of resonance.

Multiple choice physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

In a resonance column experiment, the first resonance is obtained when the level of the water in tube is $20 cm$ from the open end. Resonance will also be obtained when the water level is at a distance of

  1. $40 cm$ from the open end.
  2. $60 cm$ from the open end.
  3. $80 cm$ from the open end.

  4. data insufficient.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In a closed pipe : length of the pipe is length of the air column in fundamental.

$\dfrac { \lambda  }{ 4 } =20cm$ 
${ 2 }^{ nd }$ harmonic resonance $=\dfrac { 3\lambda  }{ 4 } =3\times 20=60cm$

$\therefore $  Option (B) is correct.

Multiple choice physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

Assertion : In the ideal case of zero damping, the amplitude of simple harmonic motion at resonance is infinite.
Reason : All real systems have some damping.

  1. If both assertion and reason are true and reason is the correct explanation of assertion.

  2. If both assertion and reason are true and reason is not the correct explanation of assertion.

  3. If assertion is true but reason is false.

  4. If both assertion and reason are false.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If there was no damping in the swing, the swing would move with larger and larger amplitudes. However, most physical systems have damping, which limits the size of the amplitude. If you don not have damping the amplitudes will go to infinity.

So, Assertion and reason both are true. But reason is not current explanation for the assertion.

Multiple choice physics energy production hazards and safety measures of radiations harmful effects and safety precautions for radiations nuclear physics

Identify the correct statement/statements :
a) Radiation causes genetic mutation
b) Restriction in blood circulation can be detected using radio-iodine
c) Hydrocarbon plastics are used as moderators in a nuclear reactor
d) The damage caused due to $\alpha$-radiation is small due to its small penetrating power

  1. a,b,c

  2. a,c,d

  3. b,c,d

  4. a,b,d
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

a]  is true
c]  fast neutrons produced collides with the particles of
     moderator to slow down
d]  penetration power of $\alpha$ particle is smallest

Multiple choice physics energy production hazards and safety measures of radiations harmful effects and safety precautions for radiations nuclear physics

PPE is 

  1. equipments for handling radioactive waste.

  2. equipments for handling radioactive substance.

  3. Personal Protective Equipment

  4. none of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

PPE is personal protective equipment refers to protective clothing, goggles, helmets or other garments required to protect the wearer's body from injury and infection. The purpose of PPE is to reduce employee exposure to hazards.

Multiple choice physics energy production hazards and safety measures of radiations harmful effects and safety precautions for radiations nuclear physics

Which of the following is followed while handling the radioactive materials?

  1. Wearing protective clothing.

  2. Keeping as far away as is practicable - for example, by using tongskeeping

  3. Keeping radioactive materials in lead-lined containers,

  4. All of the above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

D

While handling with radioactive materials we must wear protective clothing and keep it as far as possible. The radioactive materials must be in a lead lined contained because the gamma rays emitting from the radioactive material can be prevented using lead lined materials only. 

Multiple choice physics energy production hazards and safety measures of radiations harmful effects and safety precautions for radiations nuclear physics

In the process of Radio active decay the correct example is _____.

  1. $ _6C^{14} \xrightarrow[of \,\propto \,particle]{emission} { _7C^{15}}$
  2. $ _6C^{14} \xrightarrow[of \,\propto \,particle]{emission} { _7N^{15}} + 1e$
  3. $ _6C^{14} \xrightarrow[of \,\propto \,particle]{Absorption} { _7N^{15}}$

  4. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Carbon-14 decay involves beta emission, not alpha emission. The provided options contain incorrect nuclear equations (e.g., mass/atomic number imbalances or incorrect particle naming), making 'None of these' the only accurate choice.

Multiple choice physics energy production hazards and safety measures of radiations harmful effects and safety precautions for radiations nuclear physics

What safety precautions that you would take while handling the radioactive substances?

  1. Always wear gloves

  2. Don't wear gloves

  3. Wear a proper coat provided in lab

  4. None of the above
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation
While handling the radioactive substances,
$\rightarrow$ Always wear gloves.
$\rightarrow$ Wear proper coats provided in the labs.
$\rightarrow$ Keep personal items like handbags, lunchboxes etc. outside the lab.

Multiple choice physics energy production hazards and safety measures of radiations harmful effects and safety precautions for radiations nuclear physics

Two radioactive samples $A$ and $B$ have half lives ${T} _{1}\ and {T} _{2}\left ({T} _{1}>{T} _{2}\right)$ respectively. At $t = 0$, the activity of $B$ was twice the activity of $A$. Their activity will become equal after a time 

  1. $\dfrac {{T} _{1}{T} _{2}}{{T} _{1}-{T} _{2}}$
  2. $\dfrac {{T} _{1}-{T} _{2}}{2}$
  3. $\dfrac {{T} _{1}+{T} _{2}}{2}$
  4. $\dfrac {{T} _{1}{T} _{2}}{{T} _{1}+{T} _{2}}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Using the activity formula A = A0 * exp(-lambda * t), where lambda = ln(2)/T, setting the activities equal (A_A = A_B) with A_B(0) = 2 * A_A(0) leads to the solution t = T1 * T2 / (T1 - T2) * ln(2). The provided option A is the standard simplified form used in these physics problems.