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In hydrogen atom, the electron makes 6.6 x 10^(15) revolutions per second around the nucleus in an orbit of radius 0.5 x 10^(-10)m. It is equivalent to a current nearly: A. 1Ampere B. 1milliAmpere C. 1 microAmpere D. 1.6 x 10^-19 Ampere

Answer: B. 1milli Ampere Explanation: As we know; I = qV Thus, I = 1.69 x 10-19 x 6.6 x 1015 I = 1.05 x 10-3 or I ≈ 1mA... View Article

A helicopter of mass 1000 kg rises with a vertical acceleration of 15 m/s^2. The crew and the passengers weigh 300 kg. Give the magnitude and direction of the(a) Force on the floor by the crew and passengers.(b) Action of the rotor of the helicopter on the surrounding air.(c) Force on the helicopter due to the surrounding air.

Given, Mass of helicopter , m1=1000kg Mass of the crew & passengers , m2=300kg Upward acceleration of the helicopter , a = 15m/s2 Total... View Article

A steel cable with a radius of 1.5 cm supports a chairlift at a ski area. If the maximum stress is not to exceed 10^8Nm^−2, what is the maximum load the cable can support ?

Given, Radius of the steel cable, r = 1.5 cm = 0.015 m Maximum allowable stress = 108 N m−2 As we know, Maximum stress = Maximum... View Article

What is the end product when CH3CONH2 reacts with Br2+ KOH? A. CH3−CH2−NH2 B. CH3Br C. CH3CONHBr D. CH3NH2

Answer: D. CH3NH2 CH3CONH2 + Br2 + 4KOH → CH3NH2 + 2KBr + 2H2O + K2CO3 This reaction is called Hofmann's bromamide... View Article

A meter bridge is set-up as shown, to determine an unknown resistance. X using a standard 10 ohm resistor. The galvanometer shows null point when tapping key is a 52 cm mark. The end-corrections are 1 cm and 2 cm respectively for the ends A and B. The determined value of X is:A. 10.2ohmB. 10.6ohmC. 10.8ohmD. 11.1ohm

Given From given circumstances l1=52+1=53 cm l2=48+2=50 cm By using the condition for balanced Wheatstone bridge, we get X/10 = (52 +... View Article

A bottle of dry ammonia and a bottle of dry hydrogen chloride connected through a long tube are opened simultaneously at both ends. The white ammonium chloride ring first formed will be: (A) At the center of the tube (B) Near the hydrogen chloride bottle (C) Near the ammonia bottle (D) Throughout the length of the tube

Answer: (B) Near the hydrogen chloride bottle NH3 is lighter than HCl, thus it diffuses faster. Hence, a white ring of NH4Cl is formed in the... View Article

A bar magnet is oscillating in the earths magnetic field with a period T. What happens to its period and motion if its mass is quadrupled? A. Motion remains S.H.M. with time period =2T B. Motion remains S.H.M. with time period =4T C. Motion remains S.H.M. and period remains nearly constant D. Motion remains S.H.M. with time period = T/2

Answer: A. Motion remains S.H.M. with time period =2T T = 2π√(I/MB) where 'I' is the moment of inertia ∵I ∝ m, where m is... View Article

Our constitution came into force on _________ (A) August 15, 1947 (B) January 26, 1950 (C) October 2, 1948 (D) November 26, 1949

The constitution was passed and adopted by the assembly on 26 November 1949. The Constitution came into force on 26 January 1950 and this day is... View Article

Give example of viviparous animals

Animals that give birth to offspring are called viviparous. In viviparous animals, both fertilization, as well as the development of the embryo,... View Article

Find the lengths of transverse axis and conjugate axis, eccentricity, the co-ordinates of foci, vertices, length of the latus-rectum and equations of the directrices of the following hyperbola 16x²− 9y² = −144.

The equation 16x2 - 9y2 = -144 can be written as (x2/9) - (y2/16) = -1 This is of the form (x2/a2) - (y2/b2) = -1 Hence, a2 = 9 and b2 = 16 a = 3... View Article

A and B started a business in partnership investing Rs 20000 and Rs15000 respectively. After six months, C joined them with Rs 20000. What will be B’s share in the total profit of Rs 25000 earned at the end of 2 years from the starting of the business? (A) Rs 7500 (B) Rs 9000 (C) Rs 9500 (D) Rs 10000

A and B invested for 24 months and C invested for 18 months A's share = 20000 x 24 = 480000 B's share = 15000 x 24 = 360000 C's share = 20000 x... View Article

In India the largest herbarium is located at ____________ (A) Dehradun (B) Delhi (C) Lucknow (D) Kolkata

The Acharya Jagadish Chandra Bose Indian Botanic Garden previously known as Indian Botanic Garden has the largest herbarium in India. It is... View Article

_________ is the largest mangrove forest in the world (a) Pichavaram (b) Pitara (c) Sundarbans (d) Bhitarkanika

Sundarban Mangrove Forests are the largest mangroves in the world located in the Ganges river delta in Bangladesh, West Bengal. Pichavaram... View Article

Draw orbit structure diagram of Calcium Oxide (CaO)

Atomic Numbers Ca = 20, O = 8 The orbit structure diagram of Calcium Oxide (CaO) is shown below... View Article

Derive a relation between the Celsius and Fahrenheit Scales of temperature using the fixed points in the two different scales

Where, L.F.P is lower fixed point and U.F.P is upper fixed point On simplifying, we get, We get, -is the relation between Celsius and... View Article

The most of the rainfall in India is brought in by the ___________ (A) North – east monsoon (B) Retreating monsoon (C) Western disturbances (D) South – west monsoon

The south-west monsoon winds bring rainfall in India. It causes over 80% of the rainfall over the nation from June to September. The south - west... View Article

How did a temple communicate the importance of a king?

Temples were constructed as places of worship and are meant to demonstrate the power, wealth and devotion of the patron. The temples were... View Article

In a certain store, the profit is 320% of the cost. If the cost increases by 25% but the selling price remains constant, approximately what percentage of the selling price is the profit? (A) 30% (B) 100% (C) 70% (D) 250%

Let C.P. = Rs 100 Then, Profit = Rs 320 and S.P. = Rs 420 New C.P. = 125% of Rs 100 New C.P. = Rs 125 Now, New S.P. = Rs 420 Profit = Rs (420 -... View Article

If 10 times the 10th term of an A.P. is equal to 15 times the 15th term. Show that 25th term of an A.P. is zero.

Let 'a' be the first term of an A.P. and 'd' be the common difference Given that, 10 times the 10th term is equal to 15 times the 15th term. We... View Article

An npn transistor conducts when (a) both collector and emitter are positive with repect to the base. (b) collector is positive and emitter is negative with respect to the base. (c) collector is positive and emitter is at same potential as the base. (d) both collector and emitter are negative with respect to the base.

An npn transistor conducts when collector is positive and emitter is negative with respect to the base because emitter base junction is forward... View Article