Latest Posts

The kinetic energy (in keV) of the alpha particle, when the nucleus at rest undergoes alpha decay, is

<strong>Solution:</strong> The KE(m KeV) of the alpha particle, when the nucleus at rest undergoes alpha decay \(\begin{array}{l}\sqrt{2m_{\alpha}k_{1}}=\sqrt{2m_{P_{b}}k_{2}}\end{array} \) \(\begin{array}{l}=\frac{k_{1}}{k_{2}}\end{array} \)=\(\begin{array}{l}\frac{m_{P_{b}}{m_{\alpha}}\end{array}... View Article

Explain the structure of the solar panel.

Photovoltaic cells consist of two or more layers of semiconductors along with one layer containing positive charge and the other... View Article

Two bodies of masses m₁ and m₂ fall from heights h₁ and h₂ respectively. The ratio of their velocities, when they hit the ground is a) h₂ b) √(h_¹/h₂) c) m₁h₁/m₂h₂ d) h₁²/h₂²

Answer: b) √(h1/h2) Solution: When a body is at rest at height h, it has only potential energy = mgh when the... View Article

A monkey of mass 20 kg rides on a 40 kg trolley moving at a constant speed of 8 m/s along a horizontal track. Frictional force can be neglected. If the monkey jumps vertically, with respect to the moving trolley, the catch the overhanging branch of a tree, the speed of the trolley after the monkey has jumped off is:-

a) 16 m/s b) 12 m/s c) 8 m/s d) 6 m/s Answer: Solution: By conservation of momentum Pinitial =... View Article

In the situation given, all surfaces are frictionless. If F = Mg/2, the ratio of accelerations of blocks A and B is n/√5. Find the value of n. (Both the blocks have mass M)

Answer: 1 Solution: For block B, F – Mg = Ma – Mg/2 = Ma a = g/2(-j) in downward... View Article

Which one of the following represents simple harmonic motion?

a) Accelration = -k0x + k1x2 b) Acceleration = – k (x +a) c) Acceleration = k(x+a) d) Acceleration =... View Article

In an experiment to determine the focal length of a concave mirror by the u-v method, a student places the object pin A on the principal axis at a distance of x from the pole p. The student looks at the pin and its inverted image from a distance keeping his/her eye in line with PA. When the student shifts his/her eye towards the left, the image appears to the right of the object pin. a) x < f b) f < x < 2f c) x = 2f d) x > 2f

The correct answer is b) f < x < 2f Solution Determination of focal length of a concave mirror Following are the... View Article

The escape velocity for the earth is v_e. The escape velocity for a planet whose radius is four times and density is nine times that of the earth, is:

a) 36 ve b) 12 ve c) 6 ve d) 20 ve Answer: b) 12 ve Solution: Let R be the... View Article

The condition for obtaining secondary maxima in the diffraction pattern due to a single slit is (symbols have their usual meaning)

a) a sin θ = nλ b) a sin θ = (2n-1)λ/2 c) a sin θ = (2n-1)λ d) a sin θ = nλ/2 Answer: b) a sin θ =... View Article

The minimum age required to contest for the post of Vice-President of India is ________. a) 40 years b) 30 years c) 20 years d) 35 years

Answer: The correct answer is option (d) – 35 years. The Vice-President of India is elected for a term of... View Article

The minimum age required to contest for the post of President of India is ________. a) 21 years b) 35 years c) 30 years d) 24 years

Answer: The correct answer is option (b) – 35 years. The President is the highest formal authority in India. The... View Article

The Natural Vegetation of an area depends mainly on climate and hence there are distinctive areas of different types of vegetation. The governing factors in general are precipitation and temperature. Accordingly, Pine forests in India are found in _______ a) The Northern Plains b) The Himalayas c) The Coastal areas d) The Sunderbans

Answer: The correct answer is option (b) – Himalayas. The other factors influencing the growth of vegetation in an area... View Article

Jadeite, found in Daojali Hading, may have been brought from China. State whether True or False. a) True b) False

Answer: The correct answer is option (a) – True. Jadeite is a stone. It may have come from China. It... View Article

Belgium has borders with ______ a) Germany, Spain, and Netherlands. b) Netherlands, Spain, and France. c) Spain, Germany, and France. d) Germany, France, and Netherlands.

Answer: The correct answer is option (d) – Germany, France, and Netherlands. Belgium is located in Western Europe. Belgium also... View Article

Write briefly about the struggle against Apartheid in South Africa.

Answer: Separation of people as per their race is known as Apartheid. This racial discrimination was followed in South Africa.... View Article

How can citizens make the Government accountable to them?

Answer: The Governments are elected by the people. The Members of Parliament, the Members of Legislative Assembly are elected by... View Article

Do you think the Indian Princes were short-sighted in their approach to the events of 1757?

Answer: Yes, the Indian Princes were short-sighted in their approach to the events of 1757. The Indian Princes fought against... View Article

Assertion: The true Geographic North direction is found by using a compass needle. Reason: The magnetic meridian of the Earth is along the axis of rotation of the earth. a) Both Assertion and Reason are incorrect. b) Assertion is correct but Reason is incorrect. c) Assertion is incorrect but Reason is correct d) Both Assertion and Reason are incorrect.

Answer: The correct answer is option (a) – both assertion and reason are incorrect. As per change in location, the... View Article

Which five provisions of the Constitution make India a full-fledged Constitution?

Answer: The five different provisions or 6 different provisions of the Constitution which make India a full-fledged Constitution are given... View Article

Which of the following states is not among the top five populous states of India? a) Bihar b) Gujarat c) Maharashtra d) Uttar Pradesh

Answer: The correct answer is option (B) – Gujarat. Gujarat is not among the top five populous states of India.... View Article

«
1
…
713
714
715
716
717
…
5,472
»