Maths practice for 14 year olds - page 160 of 370

Number of problems found: 7385

Transformation 26951
The bell uses 8 V alternating voltage obtained from the 220 V mains. The secondary coil of the bell transformer has 60 turns. How many turns must the primary coil have? What is the transformation ratio?
Coils of transformer
The transformer's primary coil has 1100 turns and is connected to a voltage of 220V. How many turns does the secondary coil have when the voltage is 55 V? Find the transformation ratio and decide what kind of transformation.
Coils of transformer
What voltage is generated on the secondary coil of the transformer, which has 1500 turns, if the primary coil is connected to a voltage of 120 V and has 500 turns? What is the transformation ratio, and what kind is the transformation?
Coils of transformer
The primary coil of the transformer has 400 turns. A current of 1.5 A passes through it and is connected to a voltage of 220 V. For the secondary coil, find the voltage, current, and number of turns if the transformation ratio k = 0.1.
Transformer
Transformer - U1 = 230 V, N1 = 300, N2 = 1,200, I1 = 4 A. Calculate the secondary coil's transformation ratio, voltage, and current.
Candies 26871
Clara mixed a mixture of candies of two types: Ham, ham candies at the price of CZK 210 per 1 kg, and Yum, Yum candies at CZK 150 per 1 kg. She mixed the candies so that the mixture of ham, ham, yum, and yum weighed 10 kg, and the price for 1 kg of the mi
Punishment 26851
Alena, Ivana, Edo, Filip, and Martin came late to school. As a punishment, two will water flowers all over the school after class, and the other three will clean up the classroom. The class teacher couldn't decide who to send to water the flowers, so Juro
Shell area cy
The cylinder's shell area is 300 cm square, and its height is 12 cm. Calculate its volume.
The cylinder
The cylinder's surface area is 300 square meters, and its height is 12 meters. Calculate its volume.
Metal sheets
How much metal sheet is needed to produce eight 4 m long and 12 cm in diameter gutters? During production, joints are calculated at 3% of total consumption.
Which
Which of the following numbers is the most accurate area of a regular decagon with side s = 2 cm? (A) 9.51 cm² (B) 20 cm² (C) 30.78 cm² (D) 31.84 cm² (E) 32.90 cm²
Pentadecagon
Calculate the area of a regular 15-side polygon inscribed in a circle with a radius r = 4. Express the result to two decimal places.
The rectangle
In the rectangle ABCD, the distance of its center from line AB is 3 cm greater than from line BC. The circumference of the rectangle is 52 cm. Calculate the area of the rectangle. Express the result in cm².
Dodecagon
Calculate the size of the smaller angles determined by lines A1 A4 and A2 A10 in the regular dodecagon A1A2A3. .. A12. Express the result in degrees.
Circumference 26651
A rectangle with sides of lengths a, b (cm) has a circumference of 100 cm. The dependence of its area P (in cm²) on the number a can be expressed by the quadratic function P = sa + ta². Find the coefficients s, t.
Rectangular 26641
The area of the work surface of the rectangular table is 70 dm², and its perimeter is 34 dm. Determine (in dm) the length of the shorter side of this table.
Lookout tower
How high is the lookout tower? If each step was 3 cm lower, 60 more were on the lookout tower. If it were 3 cm higher again, it would be 40 less than it is now.
Numbers 26591
How many can even 2-digit numbers be created from the number 2,3,4,5 if it cannot repeat them?
Coffe cups
We have 4 cups with four different patterns. How many possible combinations can we create from 4 cups?
Alcohol from potatoes
In the distillery, 10 hl of alcohol can be made from 8 t of potatoes. The rectangular field with 600 m and 200 m dimensions had a yield of 20 t of potatoes per hectare. How many square meters of area are potatoes grown to obtain one liter of alcohol?

Do you have homework that you need help solving? Ask a question, and we will try to solve it. Solving math problems.