Q10 of 30 Page 1

At the time of short circuit, the electric current in the circuit:

A. vary continuously B. does not change


C. reduces substantially D. increase heavily


OR


Two bulbs of 100 W and 40 W are connected in series. The current through the 100 W bulb is 1 A. The current through the 40 W bulb will be:


A. 0.4 A B. 0.6 A


C. 0.8 A D. 1 A


(d) With low resistance in the connection, a high current exists, causing the circuit to draw a large amount of energy in a very short time. Hence, during a short circuit, the current in the circuit increases heavily.


OR


(d) Same amount of current flows in all devices when connected in series.


More from this chapter

All 30 →
8

When a small amount of acid is added to water, the phenomena which occur are :

(A) Dilution


(B) Neutralisation


(C) Formation of H3 O+ ions


(D) Salt formation The correct statements are :


 10

A real image is formed by the light rays after reflection or refraction when they :

(A) actually meet or intersect with each other.


(B) actually converge at a point.


(C) appear to meet when they are produced in the backward direction.


(D) appear to diverge from a point. Which of the above statements are correct?


A. (A) and (D) B. (B) and (D)


C. (A) and (B) D. (B) and (C)


OR


Consider the following properties of virtual images:


(A) cannot be projected on the screen


(B) are formed by both concave and convex lens


(C) are always erect


(D) are always inverted The correct properties are :


A. (A) and (D) B. (A) and (B)


C. (A), (B) and (C) D. (A), (B) and (D)


 11

Calcium oxide reacts vigorously with water to produce slaked lime.


This reaction can be classified as:


(A) Combination reaction (B) Exothermic reaction


(C) Endothermic reaction (D) Oxidation Reaction


Which of the following is a correct option?


A. a and c B. c and c


C. a,c and d D. a and b


OR


When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black participate of copper sulphide is obtained and the sulphuric acid so formed remains in the solution . The reaction is an example of a :


A. Combination reaction B. Displacement reaction


C. Decomposition reaction D. Double displacement


 12

In a double displacement reaction such as the reaction between sodium sulphate solution and barium chloride solution :

(A) exchange of atoms takes place (B) exchange of ions takes place


(C) a precipitate is produced (D) an insoluble salt is produced


The correct option is :