Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
Filter By
Clear Filter

All Questions

Directions for Question : Read the passage given below and answer the questions with the most appropriate choice.

 

In recent years, there has been a surge in interest surrounding renewable energy sources as a means to combat climate change and reduce dependence on fossil fuels. Solar power, in particular, has emerged as a promising alternative. Photovoltaic (PV) cells, which convert sunlight directly into electricity, are at the forefront of solar energy technology.

 

The efficiency of PV cells has steadily improved with advancements in materials science and engineering. Thin-film solar cells, for example, use layers of semiconductor materials to capture sunlight, allowing for flexibility and reduced weight compared to traditional silicon-based cells. This innovation has opened up new applications, such as integrating solar cells into building materials or clothing.

 

However, challenges remain in harnessing the full potential of solar energy. Energy storage is a critical aspect, as sunlight is intermittent and not always available when energy demand is highest. Batteries and other storage technologies are being developed to address this issue, but further progress is needed.

 

Moreover, the environmental impact of solar cell production and disposal is a topic of concern. While solar energy is clean and sustainable once operational, the manufacturing process can involve the use of chemicals and rare materials. Proper recycling and disposal methods are essential to minimise environmental harm.

 

Despite these challenges, the growing investment and research in solar technology signal a positive trajectory towards a more sustainable energy future.

Question:

What advantage do thin-film solar cells offer over traditional silicon-based cells?

 

Option: 1

They allow for flexibility and reduced weight.


Option: 2

They have higher efficiency in capturing sunlight.


Option: 3

They are more durable and long-lasting.

 


Option: 4

They require fewer semiconductor materials.


Option a

View Full Answer(2)
Posted by

K Abhishek

In a situation where a country’s government exercises complete control over its territory, makes its laws, and has no foreign authority dicating its internal affairs, what term best describes the status of this country?

Option: 1

Autonomous

 

Option: 2

Independent

 

 

Option: 3

Subjugated

 

 

Option: 4

Alliance

 

A country is known to be independent when it governs itself without any interference from any foreign power.

When it is able to make its own law, control its own territory and can handle internal matters independently. Independent means full sovereignty.

Hence, the correct answer is option 2) Independent

View Full Answer(1)
Posted by

Divya Sharma

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads

In a nation where citizens elect representatives to make decisions on their behalf, and the head of state is not a hereditary monarch but a public official chosen through elections, what form of government does this nation have?

Option: 1

Monarchy

 

Option: 2

Oligarchy

 

 

Option: 3

Democracy

 

 

Option: 4

Republic

 

A republic government is a form of government where the citizens are allowed to elect representatives to make laws and decisions. This means that the head of state is not a hereditary monarch but an elected official. In such a type of government structure, the power lies with the people. This ensures the leadership through public choice rather than royal lineage.

Hence, the correct answer is option 4) Republic

 

View Full Answer(1)
Posted by

Divya Sharma

Which term from the Preamble of the Indian Constitution aligns with the idea of promoting economic equality, similar to the situation in “Harmonia”?

Option: 1

Sovereign

 

Option: 2

Socialist

 

 

Option: 3

Secular

 

 

Option: 4

Democratic

 

Socialist in the preamble of the Indian Constitution means the idea of promoting economic equality. This would mean reducing the gap between rich and poor, and making sure a fair distribution of wealth and resources. This is similar to the situation described in Harmonia.

Hence, the correct answer is option 2) Socialist

View Full Answer(1)
Posted by

Divya Sharma

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Situation: Imagine you are planning a community event to celebrate the founding principles of the United States. You want to include elements that reflect the Preamble. Which option best aligns with the principles outlined in the Preamble of the U.S. Constitution?

Option: 1

A charity fundraiser to support local schools and education initiatives.

 

Option: 2

A fireworks display to commemorate the nation’s history and achievements.

 

 

Option: 3

A debate competition on current political issues.

 

 

Option: 4

A military parade showcasing the strength and capabilities of the armed forces

 

The Goals of the Preamble of the US constitution are -

Promoting the general welfare

Securing the blessings of liberty

Establishment of justice

Hence, the correct answer is option 1) A charity fundraiser to support local schools and education initiatives.

View Full Answer(1)
Posted by

Divya Sharma

The set of points where the function \mathrm{f(x)=|x-1| e^x}   is differentiable is

Option: 1

R


Option: 2

\mathrm{R-|1|}


Option: 3

\mathrm{R-|-1|}


Option: 4

\mathrm{R-|0|}


Option 2

 

View Full Answer(2)
Posted by

Raihan

NEET 2024 Most scoring concepts

    Just Study 32% of the NEET syllabus and Score up to 100% marks

A steel rod of length 400 cm is clamped at the middle. The frequency of the fundamental mode for the longitudinal vibrations of the rod is  2.5K Hz . Find the speed of sound in steel.

 

Option: 1

20km/s


Option: 2

25km/s


Option: 3

15km/s


Option: 4

26km/s


\frac{\lambda }{2}=distance between two connected antinode

\frac{\lambda }{2}=4\\ \lambda=8M

frequency of fundamental mode is 

f=\frac{v}{\lambda }\\2.5\times10^{3}=\frac{v}{8}\\v=8\times2.5\times10^{3}\\v=20km/s

View Full Answer(1)
Posted by

Anam Khan

If  \vec{A}=a y \hat{x}+b \times \hat{y}  then curl will be-

Option: 1

(a-b) \hat{z}


Option: 2

(b-a) \hat{z}


Option: 3

(a+b) \hat{z}


Option: 4

(a-b) \hat{x}


\vec{A}=a y \hat{x}+b x \hat{y}

{\nabla} \times \vec{A}= curl =\left|\begin{array}{ccc} \hat{\imath} & \hat{\jmath} & \hat{k} \\ \frac{\partial}{\partial x} & \frac{\partial}{\partial y} & \frac{\partial}{\partial z} \\ a y & b x & 0 \end{array}\right|

\begin{aligned} & \vec{\nabla} \times \vec{A}=\hat{\imath}\left[\frac{\partial}{\partial y}(0)-\frac{\partial}{\partial z} b x\right]-\hat{j}\left[\frac{\partial}{\partial x} 0-\frac{\partial}{\partial z} a y\right] \\ &+\hat{k}\left[\frac{\partial}{\partial x} b x-\frac{\partial}{\partial y} a y\right] \end{aligned}

\\vec{\nabla} \times \vec{A}=i[0]-\hat{j}[0]+\hat{k}[b-a] \\
\vec{\nabla} \times \vec{A}=(b-a) \hat{z} \cdot

View Full Answer(1)
Posted by

himanshu.meshram

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads

If at t=0, a travelling wave pulse on a string is described by the function y=\frac{6}{x^2+3} . What will be the wave function representing the pulse at time t, if the pulse is propagating along positive x-axis with speed 4m/s?

Option: 1

y=\frac{6}{(x+4 t)^2+3}


Option: 2

y=\frac{6}{(x-4 t)^2+3}


Option: 3

y=\frac{6}{(x- t)^2}


Option: 4

y=\frac{6}{(x- t)^2+13}


y(x, 0)=\frac{6}{x^2+3}

If v is the speed of the wave, then

\\ y(x, t)=y(x-v t, 0) \\ y(x, t)=\frac{6}{(x-v t)^2+3}\\ Here, \quad v=4 \mathrm{~m} / \mathrm{s}.\\ y(x, t)=\frac{6}{(x-4 t)^2+3}

View Full Answer(1)
Posted by

sudhir.kumar

Two parallel, long wires carry current i1 and i2 with i1 > i2. When the current is in the same direction, the magnetic field at a point midway between the wire is 10\mu T. If the direction of i2 is reversed, the field becomes 30\mu T. The ratio of i1/ i2 is:

Option: 1

4


Option: 2

3


Option: 3

2


Option: 4

1


            B_{net} = \frac{\mu_{0} (i1 - i2)}{2\pi d} = 10 \mu T

\vec{B} = \frac{\mu_{0} (i1 + i2)}{2\pi d} = 30 \mu T

Solving both equations, we get:

                \frac{i1}{i2} = 2

View Full Answer(1)
Posted by

shivangi.bhatnagar

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE
filter_img