Practice Practice quiz - general science mcq Online Quiz (set-1) For All Competitive Exams
Q-1) An electric bulb of 100 watt is used for 4 hours. The unit of electric energy used is
(a)
(b)
(c)
(d)
Q-2) Out of the following, diamagnetic substance is
(a)
(b)
(c)
(d)
Copper has negative susceptibility
(i.e. χ = –0.96). Hence, it is diamagnetic.
Q-3) An AC generator of 220 V having internal resistance r = 10Ω and external resistance R = 100Ω. What is the power developed in the external circuit?
(a)
(b)
(c)
(d)
V = 200V; r = 10Ω
R' = 10 + 100Ω = 110Ω
I = $V/R' = 220/100 = 2A$
P=$I^2R$ = 4 × 100 = 400 W
Q-4) A ray of ligh is incident normally on one of the faces of right angled isosceles prism as shhown above. It undergoes total internal reflection from hypotenuse. Which one of the following is the minimum refractive index of the material of the prism?
(a)
(b)
(c)
(d)
Q-5) The magnetic compass is not useful for navigation near the magnetic poles. Since
(a)
(b)
(c)
(d)
Near the magnetic poles, H = 0, therefore, magnetic compass will not work.
Q-6) Alternating current is converted to direct current by
(a)
(b)
(c)
(d)
Q-7) Which one of the following is a non-magnetic substance?
(a)
(b)
(c)
(d)
Q-8) Consider the following statements : - Water cannot be made to boil at 90°C.
- Charge on a conductor is mostly concentrated at places where the surface is mostly plain.
- The resistance of a fuse wire is high.
Which of the statements given above is/are correct?
(a)
(b)
(c)
(d)
- The boiling point of water is 100°C. If pressure decreases, boiling point of water decreases. Thus, water can be made to boil at 90°C, on decreasing pressure.
- It is not necessary that charge on a conductor is mostly concentrated at nearly plain surfaces.
- The resistance of a fuse wire is high, so that it can easily melt during short circuit.
Q-9) What is the difference between a CFL and an LED Lamp? - To produce light, a CFL uses mercury vapour and phosphor while an LED lamp uses semiconductor material.
- The average life span of a CFL is much longer than of an LED lamp.
- A CFL is less energy efficient as compared to an LED lamp.
Which of the statements given above is/are correct?
(a)
(b)
(c)
(d)
Q-10) Consider the following statements :
- Magnetic field produced by current in a straight wire has no poles.
- The magnetic lines of force produced by a straight current carrying conductor are straight in nature.
- To produce a strong magnetic field at its centre, we prefer a current carrying wire loop of larger radius.
Which of these statements is/are correct?
(a)
(b)
(c)
(d)
Magnetic field lines form in concentric circles around a cylindrical current-carrying conductor, such as a length of wire.
The strength of the magnetic field at the centre of a circular coil carrying current is inversely proportional to the radius of the circular coil.
i.e. the field strength reduces as the radius of the coil increases.