The polarity of an unmarked horse shoe magnet can be determined by using
option
(A) a charged glass rod
(B) a magnetic compass
(C) an electroscope
(D) another unmarked bar magnet
When an electrical safety fuse is rated (marked) as 16 A, it means it
(A) Will not work if current is less than 16 A (B) has a resistance of 16 Ω
(C) will work if the temperature is more than 16º C (D) will be blown (break) if current exceeds 16 A
The average marks obtained by the students in a class are 43. If the average marks obtained by 25 boys are
40 and the average marks obtained by the girl students are 48, then what is the number of girl students in the
class ?
Gravitational force shares a common feature with electromagnetic force. In both cases, the force is -
(a) between massive and natural objects
(b) between charged objects
(c) a short range
(d) a long range