Read the following statements carefully and select the correct option.
Statement 1: The poles of a magnet can never be separated.
Statement 2 : When a bar magnet is broken, each piece will have only one pole and its magnetism is enhanced.
ABoth statements 1 and 2 are true and statement 2 is the correct explanation of statement 1.
BBoth statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1.
CStatement 1 is true and statement 2 is false.
DBoth statements 1 and 2 are false.
Refer to the given figures and select the correct option regarding these, when they are operating.
AObject I converts mechanical energy into kinetic energy whereas object II converts electrical energy into potential energy.
BObject II converts electrical energy into kinetic, heat and sound energy.
CObject I converts potential energy into kinetic energy.
DBoth B and C
Sandhya made a musical instrument as shown in the figure using large wooden box, a broom handle and a length of string.
She tightened the string by pulling harder on the broom handle. What kind of sound will she hear now?
A A higher pitched note
B A louder note
C A lower pitched note
D None of these
What conclusion can be drawn from the experiment?
AStirring increases solubility, solubility increases with decrease in temperature.
BStirring increases solubility, solubility increases with increase in temperature.
CStirring decreases solubility, solubility decreases with increase in temperature.
DStirring decreases solubility, solubility increases with decrease in temperature.
Bob is trying to turn rod P into a magnet by the following stroking method. He finds that this method does not work. Which two of the following could be the possible explanations?
(1) He should stroke rod P with the south-pole instead.
(2) The bar magnet is not touching rod P.
(3) The bar magnet stroke rod P in more than one direction.
(4) Rod P is not a magnetic material.
A1 and 2
B2 and 3
C2 and 4
D3 and 4
In the given apparatus, air is inhaled and exhaled through tube P. Tubes X and Y are closed subsequently at different times.
What will happen when
(i) Tube X is closed with a clip and air is exhaled ?
(ii) Tube Y is closed with a clip and air is inhaled ?
Refer to the given graph.
What can be the possible reason for the change in the population of mosquito larvae in the pond?
(i) There is a layer of oil over pond.
(ii) New fish are introduced into the pond.
(iii) There is a period of dry weather.
(iv) Many of the mosquito larvae have changed into mosquitoes.
A(i) and (iii)
B(ii) and (iv)
C(i), (ii) and (iii)
D(i), (ii), (iii) and (iv)
answer is c
In which of the following cases, the frictional force between the tyres of a car and the road increases?
AWhen the road is wet.
BWhen the speed of the car increases.
CWhen the surface area of the tyres in contact with the road increases.
DWhen there are more passengers in the car.
answer is c as area in contact is more
Read the given statements regarding the lever and select the correct ones.
(i) In beam balance, fulcrum is in the middle.
(ii) A nutcracker is an example of third-class lever.
(iii) In tongs, the fulcrum and the load are at the two ends.
(iv) See-saw is an example of first class lever.
A (i), (iii) and (iv)
B (ii) only
C (iii) and (iv)
D (i) and (ii)
easy and simple if you have studied levers