(English Medium) ICSE Class 10 - CISCE Question Bank Solutions

When a ray of light travels normal to the given surface, then the angle of refraction is ______.

The diagram shows wheel O pivoted at point A. Three equal forces F₁, F₂ and F₃ act at point B on the wheel.

1. Which force will produce maximum moment about A?
2. Give a reason for your answer in (a).

What should be the angle between the direction of force and the direction of displacement, for work to be negative?

Which electrical component protects the electric circuit in case of excess current and which can also be used as a switch?

Name the wire to which this electrical component is connected in an electric circuit. 

A door lock is opened by turning the lever (handle) of length 0.2 m. If the moment of force produced is 1 Nm, then the minimum force required is ______.

A force 'F' moves a load from A to C as shown in the figure below. For the calculation of the work done, which of these lengths would you use as the displacement?

If live wire makes an accidental contact with the metal case, which circuit (A or B) in the diagram, illustrating an electric iron, is considered safe for the user (Assuming the fuse is present in the live wire in both circuits)? Justify your answer.

A metal rod AB of length 80 cm is balanced at 45 cm from the end A with 100 gf weights suspended from the two ends.

1. If this rod is cut at the center, C, then compare the weight of AC to the weight of BC. (Use >, < or =)
2. Give a reason for your answer in (a).

A person standing in front of a cliff fires a gun and hears its echo after 3 s. If the speed of sound in air is 336 ms⁻¹.

1. Calculate the distance of the person from the cliff.
2. After moving a certain distance from the cliff, he fires the gun again, and this time the echo is heard 1.5 s later than the first. Calculate the distance that the person moved.

A nut is opened by a wrench of length 25 cm. If the least force required is 10 N, find the moment of force needed to turn the nut.

The diagram in Fig shows two forces F₁ = 5 N and F₂ = 3 N acting at points A and B respectively of a rod pivoted at a point O, such that OA = 2 m and OB = 4 m.

Calculate:

1. the moment of force F₁ about O.
2. the moment of force F₂ about O.
3. total moment of the two forces about O.

A body, when acted upon by a force of 20 kgf, gets displaced by 1 m. Calculate the work done by the force, when the displacement is

1. in the direction of force,
2. at an angle of 60° with the force, and
3. normal to the force. (g = 10 N kg^-1)

Mechanical advantage = ______  × velocity ratio.

Two sets A and B each of four bulbs are glowing in two separate rooms. When one of the bulbs in set A is fused, the other three bulbs also cease to glow. But in set B, when one bulb fuses, the other bulbs continue to glow. Which set of arrangement is preferred in housing circuit and why?

The human ear can detect continuous sounds in the frequency range from 20 Hz to 20,000 Hz. Assuming that the speed of sound in air is 330 ms1 for all frequencies; calculate the wavelengths corresponding to the given extreme frequencies of the audible range

How is the frequency of a stretched string related to its length?

How is the frequency of a stretched string related it’s tension?

State two causes of energy loss in a transformer.

A wire of length 80 cm has a frequency of 256 Hz. Calculate the length of a similar wire under similar tension, which will have frequency 1024 Hz