When long dry hair is brushed the strands often move away from each other because while brushing

• air is being blown through the strands

• static electric charges are being induced on the hair

• mechanical energy is being transferred into heat energy

• the gravitational attraction among the strands becomes smaller

If the length of a simple pendulum is being increased by 4-fold time period of oscillation will be

• decreased by 4-fold

• increased by 4-fold

• decreased to half of the initial value

• increased by a factor of 2 of its initial value

Which one among the following is the true representation of (i) variable DC potential (ii) rheostat and (iii) AC ammeter respectively?

The mirror used for the head light of a car is

• spherical concave

• plane

• cylindrical

• parabolic concave

An iron ball and a wooden ball of the same radius are released from a height 'H' in a vacuum. The time taken to reach the ground will be

• more for the iron ball

• more for the wooden ball

• equal for both

• in the ratio of their weights

When an electrical safety fuse is rated (marked) as 16 A, it means it

• will not work if current is less than 16 A

• has a resistance of 16 Ω

• will work if the temperature is more than l6°C

• will be blown (break) if current exceeds 16 A

A staircase has 5 steps each 10 cm high and 10 cm wide. What is the minimum horizontal velocity to be given to the ball so that it hits directly the lowest plane from the top of the staircase? (g= 10ms^-2)

• 2 ms^-1

• 1 ms^-1

• $\sqrt{2}$ ms^-1

• $\frac{1}{2}$ ms^-1

Consider the following statements:

1. If a piece of a bar magnet is broken into two equally long pieces, the pieces will not lose the magnetic properties.
2. Magnetic properties of a substance lie at the atomic level.

Which of the statements given above is/are correct?

• 1 only

• 2 only

• Both 1 and 2

• Neither 1 nor 2

Consider the following circuit :

The current flowing through each of the resistors connected in the above circuit is

• 2 A

• 1 A

• 9 A

• 4 A

Examine the statements and select the appropriate answer.

Statement I: Convex mirror is used as a driver mirror.

Statement II: Images formed by the convex mirrors are diminished in size.

• Both the statements are individually true and Statement II is the correct explanation of Statement I

• Both the statements are individually true but Statement II is not the correct explanation of Statement I

• Statement I is true but Statement II is false

• Statement I is false but Statement II is true