User Forum

Select the incorrect statement(s).
(i) The bicuspid valve guards the opening of right atrium into right ventricles.
(ii) The semilunar valves are present at the base of pulmonary aorta and dorsal aorta.
(iii) Pulmonary vein carries oxygenated blood from the lungs to the heart.
(iv) The right ventricle is the largest heart chamber.

A (i) and (ii) only
B (i) and (iv) only
C (ii) and (iv) only
D (ii) and (iii) only

Which of the following animals is a rodent?

ASheep
BWolf
CHyena
DSquirrel

During the science activity, Ms. Rakhee conducted the following experiments :
Experiment I : 10 g of rock crystals of common salt were dissolved in 50 mL of water at °.
Experiment II : 30 g of finely powdered common salt was dissolved in 50 mL of water at 60°C.
Experiment III : 10 g of rock crystals of common salt were dissolved in 100 mL of water at °.
Experiment IV : 10 g of finely powdered common salt was dissolved in 100 mL of water at 60°C.
In which experiment common salt took the shortest time to dissolve ?

AExperiment I
BExperiment II
CExperiment III
DExperiment IV

Refer the given figure and select the correct option to complete the sentence. Organ L receives ________ and _________ from organ M.


ADigested food and nutrients
BUndigested food and nutrients
CUndigested food and water
DNutrients and proteins

The given circuit shows an electric cell connected to a bulb through conducting wires. Identify the direction of current flow in the circuit.


APQRS
BSRQP
CPQSR
DQPRS

Let ball P and ball Q both released from point O of their respective frictionless ramps as shown in the given figure. The time taken by both the balls to reach point O′ is recorded. If both the balls have travelled the same distance, then which of the following statements is/are correct about the time taken by the two balls?

I. Ball P takes a longer time than ball Q.
II. Ball Q takes a longer time than ball P.
III. Both the balls P and Q take the same time.
IV. Cannot be determined as the masses of both the balls are not given.

AI only
BII only
CIII only
DI, II, III and IV

Rahul, a class 10 student conducted two experiments as follows :
Experiment 1 : Excess calcium carbonate was added to 100 cm³ of 0.2 mol/dm³ HCl at 25°C.
Experiment 2 : Excess calcium carbonate was added to 80 cm³ of HCl of concentration X mol/dm³ and at temperature Y°C.
Following curves show results of the experiments.

Identify X and Y.

Two long current carrying wires are arranged in parallel as shown. What is the direction of the electromagnetic force on each wire?

Read the given statements and select the correct option.
Statement 1 : Work done against friction in moving a body over a closed path is zero.
Statement 2 : Work done by a constant force is always zero in a round trip of the point of application of force.

A Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1.
B Both statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1.
C Statement 1 is false but statement 2 is true.
D Both statements 1 and 2 are false.

Read the passage carefully and answer the following questions.
Two tuning forks, A and B vibrate with frequencies in the ratio 2 : 7 and their wavelengths in the ratio 3 : 4 respectively. Both the tuning forks are placed in different media.
In which of the tuning fork the velocity of sound produced is greater?

A Tuning fork A.
B Tuning fork B.
C Both produce sound of same velocity.
D Cannot say.