Two long parallel wires P and Q are held perpendicular to the plane of the paper with distance of 5m between them. If P and Q carry current of 2.5 A and 5A respectively in the same direction, then the magnetic field at a point halfway between the wires is
If 75% of the radioactive reaction is completed in 2 hours, then what would be the half life of the substance?
If the radius of Earth shrinks by 1.5% (mass remaining the same), then the value of acceleration due to gravity would change by
A small telescope has an objective lens of focal length 144 cm and an eyepiece of focal length 6.0 cm. What is the magnifying power of the telescope? What is the separation between the objective and the eyepiece?
If g is the acceleration due to gravity at the Earth's surface, the gain of the potential energy of an object of mass m raised from the surface of the Earth to the height equal to the radius R of the Earth is
A sound source producing waves of frequency 300Hz and wavelength 1m. Observer is stationary, while source is going away with the velocity 30m/s, then apparent frequency heard by the observer is:
Kinetic energy of most energetic electrons emitted from a metallic surface is doubled when the wavelength λ of incident radiation is changed from 400 nm to 310 nm, the work function of metal is:
A sample of an ideal gas is taken through a cycle as shown in the figure. It absorbs 50 J of energy during process AB, no heat during BC, rejects 70 J during CA, and 40 J of work is done on the gas during BC. The internal energy of the gas at A is 1500 J. The internal energy at C would be:
Two copper wires have their masses in the ratio 2 : 3 and their lengths in the ratio 3 : 4. The ratio of their resistance is
In which of the following process, convection does not take place primarily?
A plank of mass 2 kg and length 1 m is placed on a horizontal floor. A small block of mass 1 kg is placed on top of the plank, at its right extreme end. The coefficient of friction between the plank and the floor is 0.5, and the coefficient of friction between the plank and the block is 0.2. If a horizontal force of 30 N starts acting on the plank to the right, the time after which the block will fall off the plank is (g = 10 m/s2):
For reducing one mole of to Cr3+ the charge required is:
Arrange the following according to the decreasing order of their boiling points:
Which is not an example of homopolymer out of the following?
Which of the following metal is sometimes found native in nature?
In the following chemical reactions, the compounds A and B are respectively:
Match each item in Column I with one item in Column II and select the best match from the codes given:
In erythroblastosis foetalis, why is the first pregnancy generally unaffected by Rh incompatibility?
Which of the following diseases is caused by prions, and what is the primary feature of this infectious agent?
Which of the following characters are found in bulliform cells?
Consider the statements given below regarding contraception and answer as directed thereafter:
(i) Medical Termination of Pregnancy (MTP) during first trimester is generally safe
(ii) Generally chances of conception are nil until mother breast-feeds the infant upto two years
(iii) Intr auter in e devices like copper -T are effective contraceptives
(iv) Contraception pills may be taken upto one week after coitus to prevent conception
Which two of the above statements are correct?
If a ladder makes an angle 45° with a wall and reaches a height of 15 feet, the length of the ladder is
The difference between a two digit number and the number obtained by interchanging the two digits is 63. Which is the smaller of the two numbers?
Read the passage carefully and choose the best answer to each question out of four alternatives and mark your answer.
These days we hear a lot about science, but scientists, the men and women who do the work and make the discoveries, seem distant and strange to us. Science often appears to be very difficult and sometimes even magical. It is difficult of course, but we are wrong if we believe that we cannot understand it. The chief thing about the scientific method is that we get the answers to questions by making tests. The man, to take an example, who finds his bicycle tyre is flat will pump some air into it. Suppose one hour later the tyre is flat again, if the man is wise, he will first test the valve in water. If he finds air is escaping from it he will put in a new piece of valve-rubber and then pump up the tyre. All should then be well again. This man is using a simple form of scientific method.
If the man was very 'unscientific' he might say to himself that an evil spirit had caused the tyre to go flat.
The antonym of believe is -
1 videos|4 docs|90 tests
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1 videos|4 docs|90 tests
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